The best way to feel what it's like to have perfect arm structure at the top of your swing is by using a bucket in between your arms. The biggest errors that I see at the top of one's swing is that the right elbow tends to flare upwards and the left arm tends to extend too high on the backswing. This will often cause lack of power through the ball as well overall consistency as the arms and body aren't working together effectively.
When using the bucket, just place in between your arms and practice swinging to the top of your backswing. You should try and turn your body at the same as well hinge the wrists. The goal is to make sure the bucket stays in between your arms during the backswing and right up until impact. After impact the bucket can then displace from your arms as you do what the arms and hands to be faster than the body.
The other benefit of keeping the bucket between your arms is that you will tend to not move hands away from your body during the swing. This will help in maintaining a neutral swing path as well connecting the ball in the middle of the clubface more consistently. Also when doing the bucket drill, you don't need to grip the club. Just use the bucket by itself.
Once you have done this drill, then grip the club and use a SW. Try and simulate the same feeling doing half swings as you would with the bucket in between your arms. The more you do the bucket drill, the more you will feel a tighter sensation between your arms and your body as they will be working together. You will start having your right elbow point to the ground and your left arm lower. This will result in stronger shots.
If you'd like any further help in having the correct backswing just let me know and we'll book you in for a lesson.