High Fashion Sewing Secrets from the World's Best Designers - Claire B. Shaeffer Jam-packed with information. I've picked up more from her toss-away mentions of things to keep in mind (which she includes while she's explaining some other technique) than I've gotten from most books on sewing.

Lots of diagrams and step-by-step instructions, as well as helpful hints and photos of how the techniques are used in high fashion. Although the diagrams are clear and useful, many of them will require that readers practice the technique on scrap before implementing them in garments; it's just darned difficult to explain through text something which most people learn kinesthetically and visually. Still, highly recommended.