Here's the next step in being able to do Handstands freely. Place you hands six or so inches away from the edge of a wall. Kick your feet up, press the top of your head against the wall, and move your legs away. This will get your body in the correct alignment with your hips and shoulders stacked. Hold this position for as long as you can and you'll really feel your core and upper body working hard to keep your body up. When you're ready, start pulling your head away from the wall, balancing in a full Handstand.
Source: Laughing River Yoga Studio