Pinning Front Folds On Head

Fold the front of head toward back and pin (red pin); fold either side (from toward the front, at about 45 o from the front, rather than 90 o) over toward centre and back, making sure that the overlap covers the edge of front fold (blue pins).
I find it simpler to pin the front and front-sides down and sew them before pinning and sewing down the back.