Here's a little tutorial on how to make one (or 20!) tic tac toe blocks of your own!
Add in two strips.
Sew all the strips together and press.
Go back to the cutting board. Cut the block into 3 pieces, horizontally this time.
Trim the block down to 6.5" square.
Make a few.
Repeat as many times as you see fit!
And BAM. It turns from an orphan block to a WIP.
Just. like. that.