This is the route I took to visit some major cities in China.
Shanghai (2 nights) > High-Speed Rail (1:07)
> Nanjing (2 nights) > Flight (3:00)
> Guangzhou (1 night) > High-Speed Rail (1:20)
> Shenzhen (1 night)> Subway (0:30)
> Hong Kong (5 nights) > Ferry (1:00)
> Macau (1 day)> Ferry (1:00)
> Hong Kong > Flight (4:30)
> Beijing (3 nights) > High-Speed Rail (0:30)
> Tianjin (2 nights) > High-Speed Rail (5:00)
> Shanghai (1 night) > Flight > HOME in USA