I am going to show you my favorite stretch to help to teach your arms what to do. It's something really simple, you can do it at home and it works really well if you do it in front of your mirror. In a one-plane golf swing you are trying to swing your arms across your shoulder plane. I think a lot of people have a problem with that and sometimes they get their arms too low or sometimes they get their arms too high, they can not feel where they need to go. Do this stretch. Bend from the hips in your athletic posture, let your arms dangle , take your right palm and grab your left wrist with your thumb on top and merely pull your left arm across your body so that it covers up your shoulder. My right elbow is naturally going behind me. Not because I shoved it back there but just because when I swung across and back it slid behind and that is an important thing in a one-plane golf swing. I can do this drill in two ways. I can go up there and hold the pose or I can do repetitions between my golf grip and making that stretch. I will do both, holding the pose I do this for an eight count, as I do this you can hear the torque in my voice. I feel stretch in my shoulders, my hips, my oblique muscle. That will help me get more flexible. The other way I put my hands in a golf grip, swing them back, then do the stretch, then do the grip, then the stretch. I am just doing repetitions, teaching myself that the stretch and the backswing need to be so similar. The neat thing is that I can just turn around and do It the other way and work on my follow-through. If I just bend from the hips again, let my arms dangle and this time I reverse my hands, with the pulling hand always on top, and again I just pull my arm across my body. When I do this my arm is covering up my shoulder plane and I am still in my spine angle. I can hold the count again, I am feeling stretch in different places on this site. I can alternate between the stretch and grip drill again as well. If I put a golf club in my hand and make a normal swing you can see that the swing is very similar to the stretch that I just practiced. This is something that you can do at home on any day of the week, whether it is raining, cold or whatever, it is a great way to warm up. Do not let the weather get you down, you can work on you golf game all year around.