I believe in stating things out loud and directly, while doing it as nicely as possible. It is scary to speak up and set boundaries but it will work better in the long run --
I really like you and enjoy our time together. As friends I hope you understand what I am about to say -- quilting is my business and I am finding myself starting to resent the time I have spent quilting multiple quilts for you for free. I only meant to do one, and can't do them any more without harming our relationship. I don't want this little thing to get between us. In addition, there are some ways you can improve your tops for whoever quilts them, you, me, or someone else. If you'd like when we are visiting I would be happy to point out some of those things.