I just finished taking Linda Lee, Underneath It All, a Craftsy class, and I have never enjoyed an on line class so much. First, a bit about Craftsy classes. I came late to the table taking them. Someone whose opinion I value recommended them to me and so I hesitantly waited until they went on sale (they do go on sale for almost half price periodically) and signed up for a few.
I have always admired Linda Lee, the owner of Sewing Workshop patterns. I think she has wonderful technique, that her patterns are beautifully drafted, but most particularly because she brings beauty to the simplest designs by her innovative combinations of fabrics in unexpected ways. I find her work to be elegant.
In this class she covers various interfacings, facings, interlinings, underlinings, and linings (including drafting a lining when your pattern provides none). She teaches calmly, methodically, and thoroughly. The classes are divided into chapters and some of them are as long as 38 minutes, but the time flies by. I honestly took away so much new information, so many new ideas, and so much reinforcement of things I may have known once but had forgotten.
If you have a chance to take this, please do. Another side note about Craftsy classes. I did take one on bridal veils that I felt was not up to the standard it should be. I had found as much information on the subject from on line blogs and a book or two. When I brought it to Craftsy's attention, they apologized and credited my account. I hadn't asked for or expected that. But, I think it speaks to their desire to present high quality classes that even seasoned sewers can learn from.