I also use muslin squares or that thin batiste cotton material used nightgowns, etc. I have also used old flat sheets bought at thrift store. Just cut your blocks about 1/2 inch larger than what you want as you will do some trimming after blocks are constructed. I have used 10 inch up to 15 inch blocks. You can also play with the arrangement of the blocks. I start with strip diagonal in center and then add to left and right . As for your strips anywhere from 1 1/2 inch to 2 inches . Have fun and enjoy.