Always the big and famous city first. such as Beijing, Shanghai, Guangzhou,Shenzhen,Chongqin etc.
The traffic, services, network and essential communicating were better.

What you should know more, check the simple list below

Map & Map app
Phone & Mode Type
Mark down Destination

Map & Map app
First of all, tourist map of paper not recommend,it may hard to read and most importance is for the green. let’s chose Map APP,such as baidu , Tencent, Gaode with local map. do not  use google map by now. the POI  working good at the cities we recomemed, and it still FYI at most of the downtown and smal city. Garmin might be also working. but an APP from China will better. All of them free of charge, it may need to pay some fee by usin the mobile network.

Phone & Mode Type
China Mobile 2G：GSM 3G：TD-SCDMA 4G：TD-LTE
China Telecom 2G：CDMA 1x 3G：CDMA 2000 4G：FDD-LTE、TD-LTE
China Unicom. 2G：GSM 3G：WCDMA 4G：FDD-LTE、TD-LTE

China Mobile.. most strong network among this country.
China Telecom, speed fast
China Unicom, multi phone support

it comes out one new company,no data yet.

Mark Down Destionation
and print it’s name in hinese with your language in case get lost. it’ll save your time when asking the passerby or the driver.