Fold the piece of black foam over directly on top or slightly forward of the exact spot you tied down the green foam and tie it off. As before, make sure that you tie it off directly on top. If the pieces of foam are even they will lay perfectly one on top of the other.
Starting from the point where you tied off the black foam strip start wrapping your thread forward over the foam. You want to wrap forward so that the piece is tied down right at the eye of the hook.
Fold the foam backwards from it's tie down point to create the head of the fly. You should have a small bubble of foam as shown in the picture if you've done it right. Now you can trim your access and make sure that you have secured everything as to form a uniform collar area.
Cut four to six strands of your flash material. I like flashabou. Tie them in on the collar so that they butt up against what will be the back of the fly. Make sure you tie them directly on top of the hook shank. When you make your final locking wrap if you apply firm but smooth pressure the flash materials should splay out slightly.