Really the best advice is to go into the training room and press a button next to the enemy. Then press another button directly after. Hopefully that next attack will be fast enough to combo. Then it's kind of like a game of reverse-Simon-says as you figure out which punches and kicks lead into others.
One of my favorites is Jill's.
Basically
Hold Down, press Heavy Kick (HK), she will do a sliding sweep knocking opponent off feet onto the ground. As soon as they hit the ground, while still holding down, hit light kick. Timing will be difficult at first, but the effect should make them shudder. As soon as that kick connects, hit heavy punch, which will uppercut them into the air. Hit up and do that "light punch to fierce kick" combo, finishing with a special or super.
