The important part of your swing motion is the part where the strings hit the ball. Whichever grip you choose, you need to be sure the racquet face is vertical at contact. On the forehand, that point of impact should be a little in front of your front foot. The forehand stroke has two parts. Get the racquet back as fast as you can.
Some people have a kind of looping motion to their backswing.
The racquet head comes back high as the backswing begins. Then gravity takes over and the head naturally drops toward the ground into the proper position below the contact point. As the forward stroke begins, you swing low to high and your racquet finishes higher than the spot where you hit the ball. Other people tend to draw the racquet straight back and swing forward on the same, even plane. This usually creates a flat shot that doesn t have much arc or impart much spin to the ball.