I have always been a sewer so I've always had lots of scraps. When I got really serious about making nice quilts I began buying a little bit of the basics whenever I could....solids, blenders and neutrals were what I started collecting first. I have always loved scrappy quilts so I would buy a little of a lot of different colors and prints and then I would have scraps left from them. In my case my stash grew over time to the point I needed to organize it. I use a lot of pre-cuts now and they don't leave a lot of scraps normally. I don't think that having a stash is that important as a beginning quilter....figure out what kind of quilts you love to make first and then let your stash grow from there.