Here are 3 of the stretches I find most useful, especially for a tennis player:
This is an awesome stretch not only for your upper legs and thighs but also to work on your balance (I know personally that I could use some more of that...).
Here is another nice one for both your legs and arms/ upper body.
After a long day, downward dog is always a nice stretch to detox your mind and body. Is it just me or does it feel so good to hang upside down at the end of the day?!
I have a few more stretches up my sleeve that are better for the areas I personally need to de-stress, but the ones above are great in general for detoxing and strengthening your body!
Do you have any stretches you swear by?