I think it definitely depends on the type of photography you're doing. With landscape photography I put a lot of thought into the work that I do, and even with digital I'll often set up an image, play with composition, zoom, etc., think about it, and then decide it's not an image worth making, fold up the tripod legs and move on. This is more important to me with 120 film when I only have 12 images per roll, but I've carried it forward to digital also. If I'm shooting a flock of geese landing on a pond or something that has a lot of movement I'm more inclined to use a machine gun approach, shooting through a lot of images and then editing and deleting later. The other day I was out making photographs of the kokanee salmon spawning in the local stream. I made 131 images, of which I kept 10 and found about 3 that I was happy with.
Mike.