I constantly think when I'm taking pictures. I think about the light, where it is and it isn't. I think about framing shots. I think about making adjustments to the settings that I'm using. I think about where the next shot is going to be, what the action will be, and if I can get a picture of it. I think about the pictures that I've got and if the set is complete, or if there is action that I need to capture.
There are a lot of things that I think about in advance, so I don't have to think about them while I'm shooting. I think about what lens to use where, I think about my flash settings, I think about tripod use. I think about options, so if I am faced with a setting that is different from what I expect, I've got my alternative planned out.
Today, I have to photographic goals. I want to shoot a photo with really short depth of field and I want to take a night shot of water. I'll try a daytime shot of water, as well, so I can compare. The problem is, I need a filter that I don't own to get the daytime shot. Drat. I might get by with a close up, using a telephoto. And I'm thinking again.