With the exception of candid portraits using 35mm or 120 slr where I am looking through the view finder at the subject for the duration of the session I find that I first see the shot I want and then bring the camera to the position where I will capture the image seen. I've used my equiptment enough to have a pretty good idea what lens on what camera is going to fill the frame with the image intended and not have either too much or too little coverage. My mind seems to have latent overlays of differing framelines and when I "see" the shot there is an invisible border around it framing the "meat" of the shot. Using that latent frame I then decide which camera and lens is going to capture what I see without disturbing what my mind has put a "flag" around. None of this was intentional on my part. This effect started happening a few years after I started working in photography. I'm guessing that it comes from having looked at hundreds if not thousands of photographs with the subconscious making notes on what it likes in an image and then projecting that back onto the real world.