Don't button smash, don't run off edges, don't be characters you suck with, don't throw smartbombs then run into them, try not to be predictable (Spamming attacks, using a pattern).
I prefer PS3. Not as many break-downs. Free internet... Two years of XBox = $400. $300 for Elite, right? That's a lot of money... Plus games, at the least $35-$40...