With fast moving subjects like sports or portrait taking and weddings the thought process and planning occurs ahead of time. Positioning , lighting, the how and where of posing or who and what groups need to be taken, the mechanical things. etc. then just before clicking..."how does it look what is the expression or what's the action.
My preference (I am a novice) is landscape. So, Surf City John has expressed it best for me.
I try to answer the question, " Why am I taking this photo?" and "What do I want the viewer to see?" This I learned from reading John Shaw books.
Our eyes see much more than the camera, so what is the scene within the scene that I want to photograph. What is the specific subject and what around it either belongs or does not. Look at the foreground the background the sides and where to place the subject in the frame. When one is surrounded by 360 degrees of natural beauty narrowing it down to what can be seen in a small viewfinder and then making it interesting ia not as easy as it sounds. And , I do not want over-thinikng to take away creativity, but good composition is key. That said, spontaneity works , too. I might have "worked a scene" for awhile. Then bingo, when I turn away alnd look elsewhere, sometimes right at my feet there it is,click, presto, my favorite shot of the day!
In short, I try to think before I shoot, so when it comes to clicking the shutter don't think, just do it.
When pro golfers step up to hit the ball, it was found that the best are not thinking at all. Practice, training, repetition has been done.
Basketball players who are going up with that last second shot to win the game have said that all goes quiet and the action slows down to very slow motion as they watch the ball arch towards the hoop.