Here’s a great drill you can practice in your house or on the range that will help you to build the proper shape to your backswing and your downswing.
Using dowel rods or alignment sticks, place two on the ground that represents the target line and one extending from your club that, in theory, extends the club to nearly twice its length.
From there, imagine a laser pointing out from the bottom of your club as you take it back. While the club moves on an arc, the imaginary laser should be close to that target line. As you get to the top of your swing, the alignment stick you’re holding with your club will take over as your checkpoint to show you where your swing is in regards to the plane throughout the swing.