There are many roleplays that involve characters having superpowers out there, and there is (almost) always a rule stating that overpowered characters will not be accepted. While making a character that isn't OP is relatively easy, problems rise when said character develops and grows in power, be it in raw capacity, technique, or finding new uses of the same power. Is there a way to let characters grow in power without making him/her OP other than the obvious "start low", and if there is, what is it?