Film "consumption" with medium format, for me, is "self-regulating"; attached to a tripod, I work slowly and methodically. Rarely - except when I am confronted with rapidly changing lighting conditions - will I ever expose more than a frame on a particular setup...if I am shooting black and white. For transparency film, however, I have always bracketed my shots - sometimes just to see what an image would look like with more or less exposure.
My experience with 35mm is an entirely different "kettle of fish." With an SLR, color transparency materials are always bracketed - sometimes up to +/- 2/3, depending upon subject matter and lighting conditions. With black and white, however, largely owing to the subject matter (much of it is what might be termed "photojournalism"), I tend to be even more liberal in my use of film. When shooting with the rangefinder, however, I tend to shoot "very tight" (perhaps because I have yet to master a "timely loading" of my M6s...lol), looking more and shooting less (not wanting to be caught loading when something reeeaaalllyyy interesting happens).
All-in-all, though, I confess to not being terribly concerned about the amount of film shot: photography is something that gives me immense pleasure, so what the hey!