I recently took a 3 day class from Leslie Gabrielse, a professional artist from Holland. The class was very interesting, challenging, and exhilirating!
Leslie's techniques are nothing like those used in mainstream quilting. (He's been making fabric "paintings" for over 30 years, and only recently learned about art quilts.) He paints directly onto the fabric with acrylic paints, and attaches everything with big decorative hand stitches.
One really useful technique is that of using a sheer overlay to mark and position the fabric. Leslie uses a product called Tarlatan, available from Dick Blick. He marks his design on it, and then can mark right through it to the fabrics below. See his funky teapot, in progress below, with and without the tarlatan overlay.