Funny thing is that when I started off I used my right foot as mentioned above however when I used to come to stop lights, I would put my right foot down and push off with my left foot. However I broke my leg which permanently destroyed my peroneal nerve which controls a lot of foot movement. I can't lift my foot very well anymore and can't control my toes that well. Since then, I forced myself to stop using my left foot which doesn't tend to do weird things when I stop and I push off with my right foot which is still on the pedal.