I buy everything from charm squares to yardage-if I'm in love with the colors/pattern I buy as much as I can afford. If it's a collection, fat quarters, after that it depends on the fabric and colors. I have a cupboard full of awesome pieces that I have no idea what I'm going to make with them! But I have passed up fabric I loved then couldn't find it when I went back. Eventually you'll figure out what works for you. Since I love applique and making I Spy quilts, I can use really small pieces.