Use your non-hitting hand to "point" at the ball (it doesn't have to necessarily be a point)
Caution must be used here. This risks throwing off your takeback, weak-arm extension and forehand stroke.
When done right, your weak hand is not pointing anywhere near the ball: At racket release, it's pointing back and to the side. As you fully coil it's extended and pointing to the side. As you begin the forward swing, the weak hand it sweeps out a little and,
briefly, your pointer crosses the path of the ball.
So you normally will not actually point at the ball, rather, the ball path briefly moves into your pointer as it moves close to you.
If you decide to point at the ball for the majority of it's path, your arm will be doing all the "wrong" things in that your balance will be slightly off, you won't tend to get the right amount of rotation early enough, and you'll be sweeping your arm inwards instead of outwards, making it more difficult to fully load.
For beginners this
might be a good technique. However, for intermediate or advance players this would do more damage than good.