Some of my cotton yarn washcloths. My favorite, the knit diagonal pattern. Cast on 3, knit all the way, increase one st each row until side is 8 in (20mm) continue knitting, decrease one st each row until at 3, cast off. So easy. I use 8 (5mm) needle, but I have a loose stitch. You might need a bigger needle if you have a tight stitch.