Someone about to take a photo has to answer a fundamental question: is this the moment I want to capture? Because really, even in the age of digital photography and very large memory cards, you only get one chance. Even if it comes out blurry, that was the moment. That's what you got of it, and it is never coming back again. It's a big part of taking the best snapshot, or effectively using the time of a photoshoot. Both are just instants, and even though in some cases you can try again, it's not really the same anymore. I don't need to convince you of this.
It takes judgment. Knowing when to hit that button and commit to something. Maybe not the best photo in the world, but something. I'm learning more and more in music that technique in and to itself is not enough. You can have the best technique in the world, but without the judgement to put it to good use, you are just showing off. You have to trust yourself. Maybe the best photo, or the best drum piece, is kind of handjammed and simple. Minimal and kind of blurry. A little off focus, but really what you needed all along.