when you're confident with the trick and really good at it, afterbang will just happen. Afterbang was originally a calm, controlled landing where the skier was ready to hit the next feature almost immediately after landing. The best way to learn to after bang is to practise the trick more.
PanoJibber: "You don't want to be sponsored, you just want to ski lots."
zoocrewsk8er: "What's a ski lot?"
to truly afterbang you must embark on a deep spiritual journey of body and spirit. first you must travel deep into the woods by yourself. you must meditate for ten days straight and on the tenth day, your animal spirit guide will come to you in a dream. only then can you truly afterbang from the soul.