How many times do you hear someone tell their friend or teammate to "slow down" or "take your time" when they're about to take a shot in an important situation? It happens a lot, because it's good advice. I was in a bad slump a while back and I pulled myself out of it in multiple ways, not the least of which was to force myself to slow down.
After really focusing on slowing myself down, I began to notice that when a lot of players "take their time" they aren't really applying that extra time taken in a fully functional way. What I mean by this is that they do slow way down, they'll look at the shot multiple times, think about a bunch of alternatives, waffle back and forth between two or more choices, then once they finally make their decision, they'll shoot really fast. This is no good.
When I take my time, it's not to decide what to do. I already know what to do. Slowing down to me means focusing on the fundamentals. I make sure I have a proper stance, bridge, grip, straight arm, fluid practice strokes, and finally, I make sure to stroke like a hot knife through butter.
This is not to say that you should be rushing your decision making process. If you legitimately don't know which ball to go for or what you're going to do next, then by all means, take a little bit to think about it. Just don't think about what to do and forget to think about how to properly do it.