Nearly every new crocheter makes this mistake. I certainly did when I taught myself to crochet before YouTube was around to offer any help. What is the #1 mistake? When making a new stitch, only going under one loop of the stitch below instead of both. This leaves the other loop exposed and creates bars across your fabric. It’s not too often that we say there is a “right” or “wrong” way to do something in crochet, but this is certainly an exception. I explain more in this video. Happy Crocheting!!