Travel Light!
One suitcase or duffel bag is good. You can buy a cheap 2nd bag in China for gifts. You are allowed 2 bags on planes.
3 T-shirts or casual shirts, 3 shorts, one or two sets of “nice” clothes including long pants for Thai temples and Bangkok homestays. The weather will be mostly hot and only a little cool at night in Tibet.
5 sets of underclothes (you can do laundry at hotels or occasionally at nearby laundries)
small collapsible umbrella it’s rainy season in the south. You can purchase this cheaply when we get there.
one long-sleeve shirt or light sweater
camera if you want
$200-$300 personal spending money, also to purchase 1 dinner in Xian and lunches in Bangkok
cleaning/toilet articles (hotels will have shampoo, soap, etc)
Comfortable foot wear (running or walking shoes, not boots) plus sandals or you can buy these.
luggage lock