I’ve been meaning to do this for a while – try using some of the foundations from Miniatures in Minutes as borders.
The checker squares border uses the 13-Square foundation. The outer border uses the Square-in-a-Square foundation. Once I got past the miscalculations that are inevitable when it is my math impaired self at the helm, it all went together very quickly and smoothly. It finishes at 10 1/2".
This one may be saying, “I’d like to be a pillow, please.”