I am going to make memory quilts out of my parents clothing. Of course, it is all different types of fabric. Is there a best method to use to make sure the quilts sew up well? TIA

I haven't made one with anything but all cotton fabric before. But I would think that if you were using polyester fabric or something that has a lot of stretch you should use an iron on interfacing to control it. I'm sure there are others that will have possibly better solutions in dealing with this.

I just quilted a top that was pieced by my friend's mother and it had fabrics of all types - cotton, corduroy, polyester, shirting, - from clothing that the family used to wear. The top did not appear to have issues when it was pieced and it quilted just fine. But I agree with Aliciia, if a fabric has a lot of stretch stabilize it with a little fusible interfacing.

I would make sure that whatever pieces you choose are washable...sounds simple--but necessary.