It's worth buying a SIM card and Express VPN so you can use Google Translate and Google Maps. I don't know how else we would've survived the language barrier. (Read: How to buy a SIM card in Kunming)
We budgeted $500 per person for a week and ended up spending $750. That's roughly $100 per person per day travelling with a mid-range budget, excluding shopping (we didn't do any). Roughly $30 per person per day for accommodation. Roughly $20 per person per day for food. The attractions can be quite expensive, e.g. Yulong Snow Mountain.
Bring your passport everywhere. They're used to buy train and bus tickets, and tickets for attractions.
Don't expect clean toilets. They're often squatting toilets. Bring a small bottle of something scented if your nose is delicate. I brought a small bottle of White Flower Oil, it's nicely mentholated and useful for minor ailments like headaches.
Toilets often don't have toilet paper or soap. Bring your own tissue/toilet paper and plenty of hand-sanitiser or wet wipes.
Haggle with taxis if they don't want to use the meter. They will definitely offer an outrageous price at first, so walk away! They always come back and say ok to your price, or reduce theirs by much more. Definitely find out in advance (guidebook or hotel concierge) roughly how much fares should cost from point to point. This requires some planning in advance to figure out where you want to go.
Taxis have a taxi satisfaction rating system on the back of the driver's headrest. Often, the wires aren't even connected!
Personally, I'd avoid taking public buses because they're crowded, stuffy, no sense of personal space, people coughing and sneezing. If you have to stand on the bus, be warned that bus drivers might take corners pretty hard, leaving you hanging on to the rails to avoid falling onto seated passengers.
Don't expect to number 2 (💩) in cafe/restaurant toilets. You'll often see signs in cafes or restaurants that tell you "no pooping" or "pee only". The first time I saw such a sign I thought it was a one-off quirk. Now I've seen quite a few establishments with similar signs so I guess it's a real thing. In Salvador's, their toilet signs explained that the plumbing is old, so you can only pee. They'll direct you to a public toilet next door "for all your sanitary needs".
Ordering food is always tricky if you don't understand Mandarin. Point and order, and hope for the best.
Coffee is around ¥25-35 for a latte, I checked in Kunming, Dali, and Lijiang. That's on par with Singapore (S$5-7). Stick to tea.
At popular tourist sites (e.g. 3 Pagodas), the guided tourists come in waves. If they're ahead of you, wait a few minutes to let them pass, then you won't have to fight to see the sights!
Kunming airport is shiny and new. Reminds me a little of Hong Kong airport. The immigration and customs officers are reasonably friendly. There's a "smoking room", which is the most pointless room I've seen. The doors are wide open and smokers stand outside the doors smoking anyway.