t's very important to maintain proper form and perfect posture for this exercise, so keep your abdominals braced with a neutral spine to dissipate some of the weight from your back and onto your slightly bent legs. Also, keep the chest up and head straight - not poked forward!
Aim for full range of motion with your shoulders. Go as high as you can at the top, and get a good stretch at the bottom. Visualize Q-tips attached to your shoulders on an angle, and then try to poke out your eardrums.
When you've finished this and any other exercise that causes spinal compression, i.e. squats or military presses, try hanging on a chin-up bar for a while at the end of your workout. This will help increase the intervertebral space of your spine and instantly add a foot to your height. Caught your attention? Okay, maybe not a foot, but it'll help.