Make sure to keep your dumbbells a couple of inches in front of your body. A lot of people hold the dumbbells close to the leg, so this might feel awkward the first time you try it out.
When pulling the weight, focus on raising up with the elbow. Keep your hands fairly lose; they should act as latches to hold the weight and nothing more. This will help keep constant tension on the shoulder muscles.
As you perform each rep, you want to make sure you keep the dumbbells 3-4 inches in front of your body and focus on driving the weight up.