Just watch the footwork from a couple of tennis greats.  

Some video on using short court or mini tennis to warm up, including a look at how the pros use it to start their hitting. ...

A couple of quick videos with some examples of dynamic stretches to warm up before tennis. ...

Some fun mixed doubles video from the Hopman Cup as the pros start the build up to this year’s Australian Open. Murray/Watson vs Gavrilova/Kyrgios. ...