I vary between 60% and 110% of the pot. I c-bet top pr and lower two pr very fast, overbetting flop, and 80% on the turn to make drawers pay. However, c-betting set into 3-4 players can build a nice pot, and/or commit someone quickly.

Min betting is bad, and so is betting the same amount every time. You want to vary the bet size to keep people guessing, although at most levels, you can do around 75% and no one will notice a pattern.