The cradle, like the parallel leg ride, is one of those situations that you never want to get into. It's one of the hardest things to get out of, which also makes it very nice when you get one offensively. You'll have your opponent's head hooked with one arm, a leg hooked with the other, and your hands locked in between. Try to go for a nice butterfly lock, as all of the others are subpar in comparison.
Once you have a cradle locked up you should be able to at least score some back points, not to mention pin your opponent. Try to keep your lock towards the head so he can't kick out easily.