When thinking of personification ideas for writing about tennis, it helps to use all five senses, and perhaps to concentrate on the main props of the game, such as the raquet, the ball, the net etc. For example - we could use the sense of touch as in "the racquet slapped the ball into the face of the net" or, less aggressively " the racquet tickled the ball over the spine of the net,dropping slowly to catch the opponet completely unawares." The sense of sound is good too " the strings of the racquet sang and quivered as the ball ricocheted away." Or sight "quick off the draw, the racquet saw the ball coming" " or even " already anticipating the sweet taste of victory, the racquet somersaulted to the sky."
To personify, it helps to make sure the verbs you use are actions that humans can do and the objects you are comparing to couldn't literally do. Another aspect to look at is giving human body features to the object.
You could say the ball ate up your opponent.
The racket's torso cracked when it hit the ground after the player's angry throw.
After the ball caught the tape it moved from a walk to a roll over to the sideline.
You can do a lot of stuff with what the ball feels when being hit or what it does as it flies along. So you could say that the ball "screamed" across the court, or that it dipped its feet down to step right on the back of the line instead of going out. You can say that it tripped over the let cord and fell to the other side. You can say that someone's topspin forehand hit the ground and jumped up above the opponent's shoulder, making it hard to hit.
You can portray the racket as a person. It can punish the ball. It can be frustrated when "it" screws up -- "the racket dipped its head in shame as the volley went just wide of the doubles alley..."
Personification means to give nonhuman objects human-like characteristics. Regarding tennis, the easiest object to give human qualities seems to be the tennis ball. Since the ball is moving at a fast place in a straight line, you can give it verbs such as "leaped" or "bounded" (especially since it has to fly over the net). If the hit was weak, you could describe the ball as "shuffling tiredly toward the opponent's feet" for example. In this case, you are reflecting the human ability to feel tired onto the ball. If the ball hits the net, you can say that the net "seized" or "snatched" the ball, preventing it from crossing to the opponent's end of the court.
Of course, you can also use personification in different parts of the game. When describing the moment of contact between the racket and the ball, you can discuss how the racket "slapped" or "smacked" the ball and how the individual wires on the racket "trembled of fear" from the ferocity of the hit.