I feel your pain. I too often end up with shots left over from a roll of film and worry about wasting them on trivial shots. It's at this point that I've found that 24 shot rolls are better for me. Obviously the best way around it is like has already been said, shoot bulk film. But have you considered that medium or large format might be better suited to your style of working? Mf gives between 10 and 15 shots per roll and Lf is single shots for each exposure. Might be worth checking out.