Differential foot stress? I'm having some pain issues (won't get specific, I know not to let the Internet diagnose me) in one foot but not the other. What kinds of motions on a bike stress one foot more than the other?

So far I've thought of


the Sheldon Brown technique for mounting a bike (one foot stomps the pedal, the other pushes off from the ground)
coasting, where I have a habit of always leaving the same foot at full extension (and carrying more weight)


Anything else I've missed? I'm consciously changing my coasting posture, and trying to train myself to Sheldon-Brown-mount with opposite feet. If there's anything else I could be doing, it would be good to know.
Perfect pedaling is actually on the rare side and generally takes a lot of work to develop.  That being said many people pedal in an unbalanced way (I tend to have a much stronger downstroke on my right and upstroke on my left).  I use clipless however, so my feet are always in the proper position (for me).  If your foot position varies or isn't correct (for you) you may experience uneven pain.  It's also possible you have an unbalanced stroke.  Either of these could contribute to single sided pain.