SIMPLICITY
I'm not saying the forehand is an easy shot. But if you watch Kimiko Date hit a forehand it seems easy. Kimiko breaks the shot down to it's simplest form. She has a short back swing, a slight up-swing through the ball and a short follow through. She puts relatively little top spin on the ball so she does have less room for error if she tries to hit too hard, but she hits both forehand and backhand with precision.
date forehand animation
Kimiko's simplicity gives her the ability to prepare correctly and hit a consistant forehand. It also allows for less errors in the stroke in general. Kimiko hits a very flat forehand which in itself can be inconsistant, but her quick easy stroke makes her flat shot possible.
I think Kimiko has (had as she's now retired) the BEST footwork on the tour, any tour. Even better than Michael Chang. She is small in stature so she doesn't get to some balls, but, given the opportunity; she ALWAYS gets her feet set, she ALWAYS steps into the ball and she rarely hits he ball from an out of balance position.