I agree with the above comments regarding more knee bend and tossing more into the court. I would also suggest turning more (more of your back to the back).
The way you would use the above-identified starting points, is getting your front hip far into the court while your feet stay behind the baseline (i.e., forming archers bow ) so that the toss into the court and the straightening of your legs pushes your front hip foward and into the court. Note that the contact point, relative to your body, and your arm motion stay the same, so you should not feel like you are falling forward or hitting the ball into the bottom of the net (common occurences when you swing the same, but toss further forward). The difference is that your whole body is moving forward into the serve.