Luggage and bags:
If you are flying within China, there is a weight restriction of 20 kilos per person for checked luggage. You can carry up to 150 kilos, but you will be charged extra (not a lot) for the overage.
Toiletries and Medical Supplies: Kleenex and anti-bacterial wipes. For restroom use. A must take! Our family doctor also gave us Rx's for Lomotil and Cipro in case we contracted a stomach bug. We never did, but it was comforting to have along. He also recommended that we buy Pepto Bismol tablets and take one every morning and every evening as a preventative measure.
Photo Equipment: Remember to take enough memory cards for your digital camera. I ended up taking over 1000 photos in 18 days!
I had 3 cameras with me.
A basic (28 mm) for strangers (if you'd like photos of yourself from the trip); this works best for anyone you can find in the vicinity.
An SLR (25mm - 150 mm) for majority of the shots.
A digital camera for easy uploading & cheaper alternative to trial shots. I had 260 mb of disk space but still not enough!
In addition, for photo taking in caves, please bring along your 35mm camera. Digital camera is a poor substitute for low light condition photography!!!
Miscellaneous: Lots of courage, trust & belief that human nature is kind & good.
Luggage and bags:
PACK LIGHT! You'll pick up more stuff as you travel and buy things, and it'll just get crazier trying to keep track of everything and lug it around. Best advice is to take one backpack with minimal amounts of stuff. I made the mistake of having 2 packs, which ended up being a pain in the butt since they were so full at the end!
Clothing/Shoes/Weather Gear: It's very hot and humid in Guilin, so be sure to wear shorts! :) And make sure you get your bottled water!