Growing Appendages

First, get into a meditatave state. You need to be able to tell your subconcious. Picture your wings. Tell your subconcious how you need theses to survive. Focus on those two concepts. Needing these for survival. Show your subconcious an event, like being chased by a tiger or a lion, then escaping using these wings. Don't get distracted, else you could end up with some sort of half-wing, or wings on your front. Remember to focus on the concept of needing wings for survival. Make sure your subconcious understands this. Say it out loud if it helps emphasise your point.

The wings will take time to grow, like two, really big teeth. They will ache like a growing tooth and that spot will be very sore, hurting if pressed down on.

This can be used to grow other appendages as well, so long as you can picture using it for survival.