Yet another random tip.

In China, you should examine the sunscreen products carefully before you buy them. Available sunscreen often includes skin lightening additives. That's probably not what you want.

I noticed this while I was looking along the drugstore shelves for dry skin cream*. (Watsons, CapitaRetail Mall, Xizhimen.)

Another reported problem is that many local brands don't work, but that's a general problem with products in China.

*Also, you'll need plenty of moisturizer for Beijing. The city is dry, dry, dry: particularly in winter, but also early spring, late fall, etc.