Yes the tennis serve, arguably the hardest shot in tennis with arguably the most individuality, uniqueness and diversity you will see on the court. Let's face it some have high tosses, some have low tosses, some have tosses above their heads and some toss in front of them. Some hit flat and hard, some hit slices out wide. Others hit with back spin, while others just tap it in, some attack the backhand some hit it hard into random spots in the box. Some never miss a 1st serve, others have two 1st serves. Some have a kick serve, others have a slow flat safe serve. Some even jump in the air to hit a serve, some don't use their legs at all. What can we say, the serve is really the only shot 7 days a week that you can practice alone. The serve starts the match, the game, and every point. It even ends the point, game or match sometimes. And if you want to play tennis (especially competitively) you need a good serve.
Advice for this summer and fall:
-Find a way to go hit serves 2/3 days a week for 20-30 minutes.
-Focus on getting a better toss than you and you had.
-Full arm extension.
-Learn and/or improve on a slight knee bend and use it to push yourself up to hit the ball higher and maybe a little harder :)