In the beginning, when we learn how to do arm balances, we lean on friction to keep our legs up. When you want to advance your arm balances you need to begin to use core strength and side body stability. Instead of creating more downward pressure to add more friction, you think of lifting up. Gravity will always bring you down. No need to help it out. People have a hard time with this pose ( #airbaby ) because they think it's about friction between the knee and elbow. It's all about side body stability, squeezing in instead of pushing down. Another tip, point the fingers to the side and lean into the finger tips. The hips should stack like half moon.