i do what works.  i just beat defenses.  learning to run well is really important too.  knowing what cuts to make and what holes to run through.  but seriously, i think the most important component is user picking.  i cant stress that enough.  i get intercept my opponent 2.8 times a game, 90% of which are user.  everything is user when you get good.  learn to play defense, i like using the middle line back or one of the safeties.  cb coverage is too hard.
remember, man coverage in 09 is the shittiest thing.  if you see man, run drags and crosses and theyll be wide open every time.
running sucks until you get good.  dont give up on it, just keep practicing
i looooooooooove madden