I don't know if anyone else has this problem, but I noticed that when I cut triangles for hexagons, if I use a template that has the apex of the triangle cut off, I end up with excess fabric in the center of the hexagon. So I always cut the triangles with a sharp point at the top. This minimizes the pucker for me. When you use a ruler that has a flat top, there is more fabric at the top to bunch up.