I bought a scallop ruler. I think that is the most important thing to do. It will give you the right size to make your scallops and you want your corners to be round. Yes, Jenny Doan's YouTube video is excellent. She uses the scallop ruler and she teaches so well that a beginner could understand her. Check out her YouTube video. But be sure to buy the scallop ruler she uses. It's the best IMO.