LT for the on ball defense is good, if they're blowing by you you may be getting too close to them...for the faster guys you'll need to give a little room so you can cut them off on the drive attempts. You can also use the right stick to put your hands up to content shots instead of jumping...will give less fouls and can still make the guy miss. Use the double team to help out in the paint...hold circle or B depending on what console you playing on.
Make sure to use the defensive calls...double tapping on the d-pad in different directions will change your strategy(right is pressure shooters, up is pack the paint, etc..)
Breaking down the defenders can be tough at times against the CPU...the behind the back dribble seems to work best for me...the hesitation to the crossover can also work.
Use the motion to get guys open and hit them with the pass for the spot up shooting.(tapping L1 or the Left Bumper will do this.)