I took a class online at Quilt University by Marilyn Belford called "Realistic Fabric Portraits". Best class, by far, that I've ever taken! She's got one last class at QU before they shut down that starts on October 11th. I HIGHLY recommend it. She even had a lesson on threadpainting, which I did on the eyebrows and mustache! It was a blast, and she's very hands-on with help during the entire run of the class. She's also got a book out that has the instructions here:
http://marilynbelford.com/book/
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