Congrats on your bird! You will want to remove all the meat and fat from the tail junction ( where it attached to the body ). Next, I usually use a large piece of cardboard, and fan the tail out into the position you want. Then I cut small strips of cardboard ( 1" X 10" ), and staple them across the tail feathers to hold them in place. Then I use Borax and coat the tail junction. Sometimes I will use a 2 part epoxy clay such as Apoxie Sculpt and smooth over both sides of the junction to aid in holding tail more permanently. Other than that, just let it dry until it holds it's shape.