I really liked Ann Peterson's class on quilting big quilts on a small machine. Very informative and helpful. I also just started a couple of classes with Leah Day. For the Leah Day class on quilting a sampler, it's helpful if you made the sampler from the block of the month. I didn't so I'm just using practice squares. She does start out the class with info about sandwiching a quilt. Both teachers are good and seem to be very responsive to questions.