At larger railway stations, intercity stations, they will heavily utilize floor wayfinding. Here is Beijing West Station, which emphasizes cardinal directions on the floor as the station has a large North Square and South Square for boarding intercity trains.
Arrive at Shanghai Songjiang Station and....these look familiar.
Seemingly every station in the country uses numbered/lettered exits which makes it incredibly easy to wayfind which way you're going.
These are aided by helpful maps at station concourse level orienting you on what is where.
All wayfinding and announcements throughout the country are bilingual Chinese and English. They don't need to be in English, especially in smaller cities where literally nobody speaks it, but it was helpful for me specifically.
Gaode (AMap) has built-in station exit mapping for subways and intercity stations, so when a transfer station has twelve possible exits you can figure it out, and it will indicate which station exit is best for your journey. Japan had this in Google Maps which was especially helpful for finding accessible entrances with elevators if you have more than one item of luggage on you, as Japan does not have many escalators in their stations. Japanese wayfinding is also good but their stations are the opposite of standardized, and so every station feels like an adventure figuring out what is where. Not nearly as intuitive as the newer Chinese stations.
Every subway station I visited in five different cities had washrooms, usually on the concourse level. This station had a novelty: platform-level washrooms.
