Use China's excellent rail network like a pro — tickets, stations, and onboard basics.

City-center to city-center times are often better than flying once you count airports. Beijing–Xi'an and many east-China routes are ideal by high-speed rail.
You will need your passport. Book ahead for holidays. Arrive early; large stations take walking time. Keep an eye on departure boards and gate numbers.
Second class is fine for most tourists. First class adds space. Business class is a splurge. Bring snacks; onboard options vary.
This is where companions shine: finding the right entrance, security lines, and platform timing without Chinese literacy.
Yes, with passport ID. Booking platforms and station help both work; language support makes it faster.