for online settings you can add that you only want to play teams around your rating...somewhat flawed as you will get the 600 plus D1 teams but not as many as you do when you don't have the setting on. I played MLO for ages and would get humped by the D1 players and their allstar rosters, pass it to CR7 and let him run. You need to learn to defend that is all i can say.
Get you player in position using R2+x and then let go of R2 to for the challenge or block the pass, use second player pressure and suddenly switch players, to improve your defensive positioning. get your controlled players to move into passing lanes (useless against the speed whores though as they are off to the byline for the pull back or missle pass to a head of the attacker....each and every time....is it really any fun fellas?)
I also us L2 + x it seems to help with my standing tackles, also square when close to a player helps make a challenge.
Formation online I was playing a deep D line, might change that to counter attack though. and hope I can use the left on the d pad to get their players offside, as im doing pretty well offline at it.