A few of my favorites:
-Movements to strengthen the muscles and tendons in the rotator cuff and around the scapulae (your shoulders will thank you) - internal and external rotation, scapular retraction; Y, T, W, L's
-Single Leg Squats or Lunges to help strengthen the legs and also mimic the body positions you may use in a tennis match. Add a medicine ball to challenge your balance and strengthen you core .
-Medicine ball slams and throws. Works rotational power and core. Plus it's just fun.
-Kettlebell swings - helps generate explosive force from legs and hips, requires core stabilization, and can be used for conditioning
Ludacris: My chick bad! Tell me if you seen her. She always brings the racket like Venus and Serena!