Look at your fingers = Get stronger

It is easy to lose power in your lower hand as you look up and put all your focus on sticking the next hold. Try this experiment; Look at the fingers of your lower hand, and lock off. You will be surprised as you can lock off higher when you just concentrate on the lower hand instead of focusing on grabbing the next hold. Once you have learnt the technique you can start going for the next hold. It is not easy to change this so you just might need a friend who can remind you to "focus on the lower hand", while moving.