This is not my favorite pose. My proportions are such that I need arms that are 6 inches longer in order to get my torso parallel to the floor and feel any sense of freedom. Whereas Rodney looks like he’s floating. So I will always use a block, or, like in this case, Rodney’s ankle. If you have long legs, a narrow chest, and medium-length arms, you need a block underneath your bottom hand. If you have shorter legs and a buff chest (Rodney), then you won’t need a block. When the alignment of half-moon clicks in, it literally feels like you’re flying. Once you get the arm, chest, leg ratio worked out, focus on details. The lifted leg is parallel to the floor. I would say that the brain of ardha chandrasana is the intense reach of the lifted leg. The standing-leg butt and knee strongly externally rotate. The arms are an extension of each other as they spread the upper back and upper chest, while the neck, head, and chest work together to form a backbend and a mild twist. The gaze is at the top hand. Use trikonasana, triangle, to come in and out of the pose. Be especially careful not to load the inner knee coming out of the pose. Focus on the external rotation of the knee while descending back to triangle. This is a great pose when you are feeling collapsed, defeated, and out of kilter. When properly aligned, it gives you balance and suspension. When you use your legs this strongly, it makes you feel confident. Ardha chandrasana requires focus of the mind. So if you want to feel balanced, suspended, confident, and focused, this is your pose (even if you need a block).