That's exactly how I cover all pieces. Start at the center of one end and tack it down securely. Move to the opposite end and tack the center pulling the covering as tight as you can without popping it loose or breaking the model. From there, I pull the width tight and tack the center of each side and alternate from one side to the other back and forth until I work to the corners. At this point, I have pulled the covering so tight and evenly that it appears to already be shrunk. Next, break out the heat gun and shrink the whole panel. I never use an iron over the center of a piece, only a heat gun.

John