Oh, and closures. I've seen some adorable methods in magazines for kitchen and dining room chairs, for example. Plus the old stand-by: zippers (for example, more alternatives to my default 1" placket - maybe concentrate on invisible zipper insertion, and the best ways to utilize invisible zippers (where best to put them, for example). Zippers with welt, zippers disguised with buttons, etc., hidden zippers (not necessarily invisible, just cleverly hidden) could be a separate class, or part of another class.
I don't mean to pick on zippers (poor zippers...), but zippers are a much larger topic than I originally imagined, and invisible zippers are almost a topic unto themselves. Plus, buttons, snaps, ties, gussets, Velcro, laces - it's too big for one class (at least for my clogged brain to absorb in one sitting).