The takeaway is probably the most important part of the swing so use this drill to make sure you have this first move of the swing down right
From the top of the swing the right arm has to stay on top and throw around the body to the left, do not start down with your right arm pulling down.
The one plane swing is the way to go for consistent impacts because the clubface naturally closes on the downswing and does not require hand manipulation to square the face.