A good grip is vital for direction and also helps the wrist hinge correctly. The top hand is most important so let’s start with that. The grip should primarily be in the fingers of your top hand and the grip sits between the little finger of the top hand and the pad of your top hand.
When you look down at your top hand, you should see two knuckles. Once the top hand is on correctly, the lower hand is going to sit underneath it and you have the option to interlock the fingers. overlap the fingers or just sit the lower hand directly below the top hand. Whatever feels the most comfortable to you is good.