This has been a frequent item I've addressed in lessons I've taught, as well as something that I have to work to overcome myself.

In a nutshell, the term "analysis paralysis" is used to convey a lack of action due to overthinking of a problem/situation. Basically, we don't do anything because we are too overwhelmed with trying to think through and figure out what the best course of action is. 

It could be because we are spending too much time analyzing all of the different choices, or maybe because our brain freezes when confronted with having to make a choice, or sometimes because we aren't confident in our choice or our ability in selecting a choice, so we end up not making any decision (which, ironically, is also a decision, and is *ALWAYS* the worst decision).

Unfortunately, or fortunately, with horses, analysis paralysis is a kiss of death. When riding, you MUST make a decision. Whether it is affecting the quality of the canter, whether it is changing the length of stride, whether it is bending more, or the myriad of other things we need to do when riding. In terms of jumping, analysis paralysis may be the number one cause of poor quality jumps.

It is somewhat common for people to tend to freeze when going to a jump, especially in terms of affecting the canter and getting better distances. But my most frequently spoken word of advice to them is this:
I don't care if you make the wrong decision, I just want you to make *A* decision. Because ultimately, a "wrong decision" is actually a better decision than no decision at all. 

For small or moderately sized jumps (up to about 3'6" or so, depending on the horse), most horses can jump out of any distance. They just need a good quality canter, and for you to support them in whatever distance they end up getting. The worst thing you can do is freeze and not support them when you get a little tight or a little long. 

Another common refrain of mine is "a horse can jump out of just about any distance with a good quality canter. But it can barely be successful jumping on the perfect distance with a bad quality canter."

But analysis paralysis applies to other disciplines and flat work too. You have to make a decision on supporting with more leg, or perhaps riding more firmly into the spooky corner, or the myriad of other things we do when we ride. If you sit there like a bag of potatoes on autopilot, then you're only going to be as good as a bag of potatoes on autopilot. And you want to be better than a bag of potatoes on autopilot.

In order to ride better now, and to make progress in your riding in the future, you have to make decisions and execute. Don't let "perfect" be the enemy of "pretty good". The sooner you take a more leading role, the sooner your rides will improve drastically. As domesticated prey animals that we teach to listen to our commands, our horses look to us for guidance.

Give it to them.