If you listen to most people achieving a stroke in pool requires a lot of hard work and time put in on practice. If you don't understand how a stroke works it can take you years to become accomplished at it. If on the other hand you do understand the principle behind a good stroke it is easy to learn and can be accomplished in a fairly short time. If you watch players that haven't developed a stroke yet you will find that most of them seem to stroke well until the final forward movement of the cue. They take 3 or more warm up strokes that look like perfection then on the final stroke manage to destroy the entire illusion.
The most important thing to perfecting a good stroke it to first decide what stroke power level is required for what you are trying to accomplish with the shot. You should divide your stroke into at least 10 levels of speed with the majority of you shots falling between a 1 to 3 1/2 speed range. There is no shot that I can think of that would require a speed level greater than 5 except for the break. Once you have decided on the speed level for the shot stroke it at that speed. Here is the important part. On the last stroke make sure that you don't increase the speed of your stroke. If you change the speed of your stroke you are no longer shooting the same shot that you were practicing with the warm up strokes. The result will probably cause you to miss the shot if it has any degree of difficulty. As the tip contacts the cue ball the cue stick begins to transfer power to the cue ball and the stick begins to slow down. At this exact point you must increase (ever so slightly) the power of your stoke to maintain the original speed of your warm up strokes until the cue ball begins to pull away from the tip of your cue. Let your arm come to a stop naturally and don't force an extended follow through. If you practice this technique you find that in a short time you will have a phenomenal stroke with highly increased accuracy.
I think one reason players tend to increase speed on the contact stroke is because they are trying to hit the cue ball with the tip of the stick. Forget about hitting the cue ball other than to make sure the tip goes through the spot on the cue ball that you intended. Focus your concentration mainly on maintaining the speed of the stroke throughout the shot as you send the cue ball to its intended target.
