I decided early on that I wanted something on wheels. My son said I should bring a backpack, as he did when he left for China. That's the easiest way to get around, he said.
So I got both wheels and a backpack. I got a rolling backpack with smooth inline-skate wheels. And it worked very, very well. Although it wasn't quite as comfortable, perhaps, as a regular backpack, it made up for it by being very versatile. I LOVED that I could roll it on streets a lot and stop carrying it. The straps were very comfortable, and it complied with the airline regulations for carry-on luggage. I'd recommend it.
Of course, the biggest problem when I started to pack for China travel was that I had a hard time fitting everything in my bag that I thought I couldn't live without for two weeks. But you soon realize that you can live without lots of stuff when you're in China, and you can get your clothes laundered along the way pretty easily and cheaply.
Adapter for China travel
One thing I didn't want to do without was my hair dryer. Some might think that that's definitely something you could do without, but I didn't see it that way. So I brought my little hair dryer, and I went to Radio Shack to buy an adapter for China travel.
If you're bringing anything that has to be plugged in, you will need an adapter to make it work in China. I'm not sure if that's something you could find once you get there; in any case, I bought it in the United States before I left.
Beyond that, definitely pack comfortable clothes, comfortable shoes, a waterproof jacket and clothes that you can layer depending on the time of day and the weather. Remember that many places in China don't have heat or air conditioning, so check the weather forecast before you leave and plan on relying on your clothes to keep you comfortable.
On my first trip, we had a rainy, chilly spell, and I happened to catch a cold at the same time. I was FREEZING! I ended up buying a winter jacket in Lijiang because I just didn't have enough clothes to keep me warm. Luckily, with the exchange rate what it was (and is), it set me back only about $15 US, but was priceless to me.
And of course, don't forget batteries, pen and paper, and all those little hygiene essentials. A health-care worker suggested I eat one Pepto Bismal tablet with each meal because Pepto Bismal has something in it that kills some bacteria ... just in case.