Brent Abel of WebTennis.net demonstrates a simple two player drill for dramatically improving your return of serve, especially in doubles.

This is a great drill to help sculpt many areas of your game. This drill works on movements, forehands, backhands, approach shots and volleys. Great for intermediate players.

Modern topspin forehands and two-handed backhands are very similar. Players find the ball from below and lift it up, swinging across the body, and finishing over or close to the opposite shoulder