Check out this article on hand stand. In particular, in the section about handstand preparation, Build Your Foundation, she suggests: "Ardha Adho Mukha Svansasana (Half Downward-Facing Dog Pose)—standing with your legs perpendicular to the floor and bending forward to place your hands on a wall a little above hip height—is one of her favorites. Bending and straightening your elbows not only helps you find just where the tight spots are in your shoulders, it also helps you discover how actively pushing with your arms and hands can help open those knots. And keeping the spine extended in Half Dog, instead of sagging where it's most flexible, helps you learn to maintain the same integrity in Handstand."