When shooting kick shots, many factors come into play. English & speed, will all play a part in the path of the CB, and may affect the ultimate OB path as well.
To understand the issues that can affect your success, I will first explain the principals of speed and english.
To see the different CB reactions in the speed of a shot, look at Diagram 1. If you center hit a left angle kick shot with no english, medium speed, it will come out at (A), then try to do the exact shot again, only with a harder stroke, the angle of rebound on the CB will come up narrow (B), again with slow speed and the CB will go wide (C). Why? The speed of the ball hitting and compressing the cushion causes different secondary effects. Speed of the kick shot is very important and can be used to advantage.
In this discussion, "english" is defined as only side spin on the CB, it does not include draw or top-spin.
To see the different CB reactions using english (CB side-spin) on a kick shot, look at Diagram 1 again. If you center hit a left angle kick shot with no english (Diagram 1), medium speed, the CB will come out at (A), then try to do the exact shot again, only with a 1 tip of left english on the CB, the angle of rebound on the CB will come up wide (C); hit it again with 1 tip of right english on the CB and it will go narrow (B). Why? Because the english on the CB causes it to come off the cushion at more or less of an angle, depending on direction of CB english.
There are also effects of rebound that occur depending on whether the CB is "back-spinning" or "stunned" (not spinning) off the cushion, but those are more advanced topics not covered here. The assumption is that the CB will begin rolling forward somewhat on all the shots I cover in this exercise.

Diagram 1
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(I show the table diagram code below each diagram so you can copy it for future reference.)
Now that the technical aspects of how hard it may be are behind us, what I want to talk about here is how to "Make a Kick Shot". How do you measure the angles of a shot into and off the cushion? How do you know where to hit? How do you know if more/less speed, or english is necessary?
You may have heard of "angle-in vs. angle-out" on a bank or kick shot. It works assuming other factors are taken into account, such as speed and english, as noted above. What about those times where those angles are not obvious, or where the position of the balls makes it almost impossible to observe angle-in/angle-out? The most important question, is how do you do kick shots consistently? The angle in vs. angle out concept is applied here but this technique teaches you how to "find" the CB contact point on a kick shot, or the apex of your shot so the trajectory of the CB following the angles in/out are correct.
I have not seen this process for calculating CB contact points for kick shots anywhere else, so I might be the first to come up with it, even though I suspect many pro's have this in their heads. I modeled this kick shot process after a similar bank shot method I wrote about in another article that was taken from some tried and proven techniques from various instructions from various pro's that I condensed into understandable steps. I thought about this for quite awhile until I figured it out...I made so much money on the bank shot tutorial, I thought it only natural to come up with a kick shot tutorial...now I'll be twice as rich... ;) LOL...2 times 0 is still 0...
Anyway, I digress and dream of finer days when grass was green and times were good and right after the baseball game there were milk and cookies on the table.....Oh I'm off subject again, back to the kick shot!
Looking at Diagram 2 below for reference, if you follow the steps you will understand the process.
Set up your practice table for the kick shot with the CB and OB at the approximate positions shown in the diagram, then;
Step1: Draw a straight line from the center of the CB to the cushion you intend to bank from. (Line A) (Where the CB is does not matter, as long as it is in position to make the kick shot bank and the path to the OB and OB to pocket is open. You can use any of the below diagrams and move the CB and adjust your measurements accordingly. That way you can practice a allot of variations of these shots.)
Step 2: Draw a line between the object pocket through the OB and place a "ghost ball" directly on that line just behind the OB -- I used the 1 ball in the below examples. Here I use a Yellow Line. (not to be confused with the A line) (Make sure you put the pocket end of this ghost ball line at the best point of pocket entry to assure the best odds of making the shot. In this example, I have it going into the pocket to clear any cushion tip.)
Step 3: Now draw a line from the center of the ghost ball to the line A cushion point; here I use an "Orange" line (B).
Step 4: Now draw a line from the center of the ghost ball parallel to line A to the same banking cushion as the A line is pointing to; here I use a "Blue" line (D).
Step 5: Now draw a line from the center of the CB to the point where the blue line D meets the cushion. This line is shown as a "Green" line, C.
Step 6: Where Line B and C intersect, (the X) draw a line parallel to line A and D to the same cushion; here shown as the Black line.
Note: The CB diagram in the upper left corner of the table shows hit and speed, it is the same for all shots in this tutorial.

Diagram 2
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Your CB contact point on the cushion is at the arrow point on the Black Line. Hit your CB at the cushion with center hit, no english, top or bottom, and hit at medium speed. The CB will contact the cushion, and bank into the OB on the rebound, pocketing it (if you hit it right). Just as in shooting cut shots, depending on angle of approach, you will have to compensate your aim more or less to make the CB actually hit the contact point. On longer shots, the CB will roll forward more and tend to rebound wider... so you will need to compensate the aim slightly outside the angle of aim. On a kick going left, aim slightly right and visa-versa on right kick. How much depends on distance, cushion and CB speed. Practice this to find out how it works on your table.
Of course in this example we ignore the fact that the CB will likely scratch in the side pocket. I tried this shot several times and made it but also scratched. The reason for this example is to show that bad things can happen...so you might want to try the next shot instead.
Other considerations: If you come up short (not enough angle), you hit to soft...long (too much angle) you hit too hard, assuming you put no side english on the CB. In that case you will cause the CB to go off path either way depending on english. That is why I suggest, until your skill is more advanced, shooting these shots with NO english or top/bottom so the effects of ball speed, cushion compression/rebound, and english are minimized.
Notice also, how the A, B, C & D lines form two triangles. If the CB and OB are aligned the same on the table, the triangles will be almost identical. In all cases one triangle will be the upside down mirror image of the other, but a different size depending on positions of the CB and OB....just an observation I noticed I thought I would share (geometry at work!).
Once you master this technique you can move on to hard/soft and english variations. Sometimes those shots come in handy if other balls are in the CB path. After you do this many times in practice you will learn to closely approximate the position of the kick point, thus making all this measuring unnecessary. The more you do it, the better you get at it!
To show the above diagram with the trajectory of the CB, note the below diagram with heavy black lines on the CB path for the kick shot, and also notice the angle in vs. angle out perspective between the black lines and the table using the measuring system presented here. You can take any of the below diagrams and draw the same angle in vs. angle out lines. (Hint: Copy image into PowerPoint and draw lines.)

Diagram 2 with CB angle in vs. out lines, showing kick shot
Below are more examples but the lines and descriptions above are all used over and over for consistency. I provided many kick shot examples so practically every situation is covered. Those I didn't cover would be easy to create using the same techniques. I suggest you copy the table code and paste it back into the table diagram on your computer so you can recreate the shot I provided, then modify it to create your own variation of the shot. I would also save them so you have a library of possible kick shots for future reference.
This next shot is just like Diagram 2 but with the center pocket as the target. Notice how when adjusting the Orange, Blue and Green lines, to the new position of the 1 (ghost) ball, the black line point of contact has moved slightly to the left so the CB will hit the 3 ball on it's top left versus the Diagram 2 shot where the CB hits on the right side of the 3 ball. This alignment technique is very precise, as you can see.

Diagram 3
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Now on to other diagrams; I will forgo the 6 step explanation since it is repeated each time on the colored lines, only the ball positions change as do the shots. Some of them are easy some are very difficult.

Diagram 4
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Diagram 5
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Diagram 6
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Diagram 7
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Note in Diagram 8, the further down the CB is the more to the left the kick contact point, conversely the further up the CB the more to the right the contact point will be. This information is useful for future reference so you remember basic shot position dynamics.

Diagram 8
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In a more practical example, the 3 ball in this case, is an easy side shot, but what if other balls are in the way and it is your only shot? Note also in this case, the 1, (ghost) ball, is aligned slightly off line so you won't scratch with a straight in kick shot -- something to keep in mind.

Diagram 9
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In this next example, a similar slight off line shot is required to not scratch. Also note that the shot will require the CB to barely miss the side pocket. Sometimes a shot like this will require slight english, hitting before or after, if the kick point is on a pocket (a more advanced shot for sure!).

Diagram 10
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Here is an example of a longer kick shot, similar to the last one.

Diagram 11
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If you make this one consistently, you can turn pro tomorrow.......

Diagram 12
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Diagram 13
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In case you didn't notice, all the shots up to now have been "left" kick shots...Now for some "right" kick shot examples, and maybe some that are more typical of when you want to use a kick (your odds of making it are higher because they are easier).

Diagram 14
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This is a typical shot where your opponent scratches on purpose, leaving you behind the line to make your next shot harder...just kick it in. (Some rules require a ball in hand behind the line (called the kitchen), and you must hit a cushion past the line to make a legal shot).

Diagram 15
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1E5%]D1P6%^Z2P5%eB5a3%_s3C3%`q1D7%ap1E5)END
Here is a shot that comes up all the time where you might want to use a short kick shot to get better position on the next shot, which could be the 8 ball. (This shot's colored lines look odd, but remember they reference to the banking cushion.)

Diagram 16
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This next one is a shot I have seen in numerous games. It comes in real handy.

Diagram 17
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1V3%]^8D4%^^8N6%eB5a3%_s0Z4%`r5X8%ar0V3)END
After you practice some of these shots, I would suggest you memorize the contact points and variations needed for various similar shots...how to go longer or shorter on the contact point to make similar shots. This knowledge will come in handy as you will not only know how to make these shots but how to adjust to changing conditions.
As you can see the process of calculating the contact point for the kick shot is pretty consistent. Just remember on longer shots it may be a very difficult shot to make due to speed, spin or other factors. Good Luck on your kick shots, as this is not an easy skill to master. Also remember, kick shots are generally called, a desperation or last resort shot, but practicing these shots and knowing how to do them will increase your odds of making the shot if you are forced to make one in those do or die situations.