Toiletries and Medical Supplies: moisturizer and lip gloss is a MUST especially for travellers who hails from humid countries. Lanzhou's weather is DRY. Also BYO your own tissue cos most toilets DO not supply.
Miscellaneous: Coffee lovers, BYO your 3 in 1 coffee. There's no Starbucks or whatsoever, if you're lucky to find one, it taste funny. If you're lucky enough to find a packet of let's say Nescafe, it'll cost you much.
Luggage and bags: See what we have done here, we packed a pair of shoes cost RMB35. Nothing much to pack but in December with -10 clecius, we have to wear something, but don't worry you can buy them here for some unbelievable price.