Here are some tips to help you move better in the backswing:
1. Make sure you are in an athletic stance to start (neutral posture)
2. Begin the backswing with your arms and torso
3. Allow the lower body to move to help get more torque at the top of the backswing (See the pictures below illustrating the differences with and without hip turn)
4. Try this drill from the experts at the Titleist Performance Institute to get those hips in gear
http://www.mytpi.com/exercises#reach_over_the_fence
*Swing Tip Suggestion: think of moving your torso or belly button rather than just your shoulders in the backswing to help your hips rotate more in the backswing
Next time you are at the range, add a little but more hip turn to really help your low back, improve your length of backswing, and give you more distance. Happy Practicing!