It might be his most beautiful shot, and it's almost impossible to imitate. Roger Federer cocks his racquet up around his ear to increase the radius of his swing, creating more racquet-head speed and spin on the ball. Try it, and you'll likely hit a lot of shots off the frame.
The lesson: Instead of trying to knife the ball the way Federer does, watch how his shoulder turns and how he swings his left arm back as his right arm goes forward. "This keeps you sideways so you can stay in the shot longer," Macci says.