I sometimes make different type of commitment to myself. I shoot macros and what with the high magnification and all the crawling around in the mud, there is the temptation to shoot off as many as possible once you get an insect acceptably in focus. I know a lot of digital shooters take the machine gun approach to insect photography - handheld flash and all - and then crop and sharpen wildly to get acceptable results.
However, in my attempts to resist this sort of approach, I often say to myself when I am going out to shoot at dawn that I will make no more than, say, 6 exposures. It forces me to be meticlous with the framing, metering, focussing, even if it means missing some shots. Once I reach my quota, I pack my things and go home even if there are more shooting opportunities.