I've taken a whole bunch of them, mostly quilting. I've watched Leah Day for many years, receive her newsletter and thought about taking her class for many months before I decided to go ahead and take it. I have learned a lot from her class, more than I thought, I would actually. "Design It, Quilt It" with Cindy Needham was also very beneficial. She comes from a hand quilting background, but uses her domestic machine now. She's also been an educator for Superior Threads, so her teaching skills and expertize are very evident. One thing I really like, is you can ask questions and even if your question isn't directly related to the class, they will still answer your question. I had some questions about a quilt I was working on and got answers from people I felt were professionals - awesome! I've also taken 2 knitting classes with Stephanie Japel. Her enthusiasm is wonderful. I like how the camera gets very close up so you can see what's happening with the knitting needles. I think taking a class is a good way to learn new things or a different way to learn something you might already know how to do. This method is great, since you can do it at your own pace and time frame. You can ask your own questions or answer other peoples questions. I've also taken some of the FREE classes and they have all been good. Since they've got a sale going on right now, it would be an easy way to jump in and learn something new or learn a different way to do a method you are already familiar with.