I have made rag quilts with 9 to 10 inch squares and they were fine. I use cheap solid flannel for the middle layer (as batting). I wash everything first. The cutting is tedious but that takes all the time, the rest is easy. I have seen a rag quilt with a scalloped border and a Log Cabin rag quilt. Pretty clever.
Looking forward to seeing your post with a picture.
judee