1. The single fold brush. I had a highlight brush for this, but I've found it's much easier and more accurate to use this brush, dupe the layer, and invert color to create the highlight.
2. The straight folds shadow brush.
3. The straight folds highlight brush.
4. The flowing folds shadow brush.
5. The flowing folds highlight brush.
6. The sweeping folds shadow brush.
7. The sweeping folds highlight brush.
Please don't ask me how to make brushes out of these images. If you don't know, there are a bajillion tutorials (or your Help file) that'll tell you.
Enjoy! Make pretty things!