There are some comprehensive rental agencies that specialize in finding apartments for foreigners. They represent high value apartments in high demand areas, which generally rent for around 8,000- 20.000RMB per month. They provide English-language services, help with setting up Internet and TV services, and bill payment, and may even check the utility meters to help you understand where exactly your monthly payments are going. You can find a list of some agents here:
http://www.shenzhenparty.com/apartments/realestate-agencies
If you know where you would like to live, you can go to the neighborhood and find a number of small storefronts with listings on the outside windows and a bunch of young agents inside decked out in business casual attire. You can' t miss them. They usually don' t speak much English, if any, but if you give them an idea of what you are looking for they can show you some options and communicate the basic numbers involved via phone translation.
Some common agencies: Lianjia, Centaline Property, Midland Realty, Jiajiashun Real Estate, Century21.
There are also freelance agents who work via WeChat moments and groups, and they often charge lower agent fees. They develop a list of represented properties and post vacancies as they open up. They will also help you narrow down a list of apartments based on your particular needs. These agents usually have a larger pool of low-priced apartments to choose from because they work for both locals and foreigners looking to live farther away from the city center. The bottom of their price range is usually around 4,000-5,000RMB per month. Ask around in expat groups and surf online to locate some of these gems.