However, there is a wrong way to use them and one mistake I see every day at the gym is poor form. This means slouching over the display and/or resting all your body weight onto the handles. Doing either of these poor form culprits limits your muscle usage and increases your risk of injury. Standing upright and using the rails for balance works your core for balance and support — so try to stand-up straight.
I like to alternate which hands I am using to balance since I have found that if I have both hands on the machine, I will put too much weight on the handles without noticing. Try going one minute holding on with your right hand, then another minute holding on using your left hand.