Originally Posted by Kassaundra

Carol, my inner square is cut at 2 5/8, and the outer triangles are cut at 2.5 inch square and cut diagonally.

I sew opposite ends first then trim the dog ears and press then do the opposite corners. I hold the inner square folded over good side out, and the corner folded over good side out meet up folds, (for exact center) then hold in place unfold and sew.
It make a near perfect size just a tiny bit of trim.