to do the powerful serve u need to time it right when your charter throws the ball in the air and hit it in time. I do it a lot once you have it down you will mostly always do it. The other stuff idk
Yeah pretty much sums it up. Emulate tennis into this game and focus on doing powerful serves that have a 'spin' to it (tilt the Wiimote up down a bit).
Its all about timing. Once you get it down its real easy. Even easier if you know how to play tennis.
You can time it perfectly by listening to the "wooo" sound coming out of your wii remote when you point it up to serve. Throw your remote down exactly when this sound stops. This takes a bit of practice. I hit a power serve almost every time. =D