Everyone is creative, let's get that straight first. For some it just comes easier than it does for others. One trick is to relax and let it flow, no stress, no pressure. Find a comfortable seat, enjoy a relaxing beverage, maybe a piece of chocolate (or two), jot down all your ideas...good, bad, and otherwise...and don't rate them in any way as you write/sketch. Any one of them can trigger a new thought and send you off to a whole new idea that turns out stunningly.
There are millions of ways to put fabrics together into a quilt. Your sister suggested just one of them. That leaves you all the others to play around with until your "Aha!" moment strikes...and it will. I promise.
