Sometimes I mark it. I’ve used a Hera marker and washable pens. I do not use the heat erase pens as they can leave trace marks. I had this happen on some but not others so test if using the heat erase pens. I’ve also traced a design onto examination table paper (purchased online), pinned it to the top of the quilt and then quilted through it. And sometimes, I just wing it. It really depends on the quilt I’m working on. And my mood at the time😬