Sculpting decent clothing is a big challenge....one with very few tutorials, surprisingly. I did a lot of digging to find these links, and I still wish I could've come up with more....But here's what I found.
Very short, Picture only tut:
Basically Useless Video (lol):
Slightly More Helpful Video:
Helpful Tips on Basic Clothing Sculpting:
Short Tutorial about Skirts:
Long Tutorial (it covers a lot of topics, including clothes):
Quick and Helpful Tut w/ Pics:
Another Mini Tut. Show how to make a tri-fold hat:
Decent Draping/Folds Tut:
Pic-less Tut on Capes and Cloaks:
*NEW* Pretty Helpful Tut on draping and making a hood:
That's all I could find so far....But I'll keep on hunting and update here with anything I find.