A 3 1/2" circle will make a yo-yo about 1 1/2 across. I turn under about 1/4" and from the wrong side of the circle do the running stitch in the middle of the 1/4 turn down and then at the end pull the thread tight to close the hole. That a few stitches in place and stick the needle inside the yo-yo and come back out a ways from the end. cut the thread and the tail will be inside the yo-yo.