Headstand is the epitome of strength. When you see your body in a straight line holding stable, it's the best feeling ever. This is a posture to help build confidence to go into full expression of headstand.
Place the hands around the head and make sure the weight is held in the forearms. Shift the weight to the forearms and out of the feet. Slowly lift the feet to 90 degrees. From there, keep the core engaged and bend on knee to the chest. Slowly moving from the glute lift the other leg straight up towards the ceiling with foot flexed. This can be done on a wall or using the TRX until one is comfortable enough to do it without any supports.