Here's a small tip on how to make your cross actually land...
When in doubt, jab.
If you jab with your left, move slightly towards your left.
If you move to your left jab again.
If you're standing 45 degrees to his right throw the cross through his defense.
I love slipping in those crosses, they're sneaky!
Another tip is; if you're going to attack, move forward and move left or right so you're standing square against him from an angle, not square against each other, if you do, chances that he'll be able to block or escape attacks are a big higher.
Nobody can figure out where the punches come from when they're being punched, so always attack from an angle, never straight on.
I got two fists.. Don't make me use my head as well!