A killer crossover isn't how good the crossover looks, it's how the defender reacts to it.
I've heard so many people say they have a killer crossover and it sucks. This is how you really do it.
Start with the ball in the strong hand (right for now). First, look at your defender and figure out what kind of defender he is. This will help do the the cross better. Start with ball in hand and take a quick step forward with right leg and put ball between leg to left hand. If your defender jumps backward, the cross will work, if he is not fazed by it do the move again and go past him. Now after you have figured out what your defender jumps, you can do the crossover.
Now, start with the ball in the weak hand, put it between your leg to the right hand and while doing that, take a quick side hop while dribbling between your leg when you see your defender start to hop to where your going, and he will if he's a good defender. Then plant your left foot on the ground and take a side step with your right and then cross to the left hand and don't stand there and let your defender recover, dribble to the hoop and dunk.
Practicing with a defender will help you do the crossover better.
Get quick hands and feet to really throw of defender.
Instead of crossover go between legs or behind back or do a spin move.
Will scare your defender and give a shooter more room to shoot
This basketball drill is licensed under a Creative Commons License. This drill is from Pål Degerstrøm at www.degerstrom.com/basketball.