Having a good transition at the top of your backswing is important for hitting good golf shots. It's important for the transition to be smooth. You want to pause for a brief second as you transition from the backswing to the downswing. Feel that the hands, arms, body, and club all stop together.
It's also important to have good balance at this point in the swing and stay in good posture and angles. Try to maintain your spine angle at the top of the backswing and keep the right knee flexed. This will give you more power as you make your downswing and also help your club stay on a correct swing path.
Some drills that can help you pause at the top of the swing are saying the word pause at the top as you actually pause. Counting in the swing by saying 1-2 in the backswing, pause at the top of the swing, and 3 in the downswing can also help your overall tempo but is especially helpful for the tempo in the transition at the top of the swing.
Another simple tip is try to feel like you finish your backswing and then start your downswing or think of these as two separate motions. Don't blend the backswing and downswing together too much because you'll end up losing power and momentum in the swing. A solid pause at the top is a big key to transitioning correctly.