Well, as a pro golfer who has studied golf for as long as I can remember, one of the worst flaws in golf is hitting the golf ball with your hands from the top. The best way to solve over-the-top slice/hooks is to start your downswing with your lower body.
I have outlined the details on how to start your downswing with the lower body plus a simple exercise you can do to ingrain this golf technique over at my golf blog.
Check it out as it can potentially turn you from a regular golfer to a scratch golfer.
Once you master this method of starting your downswing with your lower body, you should be able to hit the ball straighter, further, and also be able to control the ball better.
The greatest part about swinging like this is that once you master it, you can hit the ball as hard as you want AND your ball will go even straighter/longer.
Of course, this is something I learned from Ben Hogan’s Five Lessons. He doesn’t outline every step but I have added some exercises that can help you feel what he’s trying to teach in his book.