When you are shooting or doing a lay-up, press O. Then wait until the halo around the ball is green, once that is accomplished, press O again and you should have the perfect shot. Luckily for dunks, you don't have to wait for the green halo. But make sure you are close enough if you want to perform a dunk.
When in a tournament or franchise, do not trade in that trade in the home screen. The teams will not take your players, but in the home screen they will take anything.
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