baka = crane
Squat down with your inner feet a few inches apart. Separate your knees wider than your hips and lean the torso forward, between the inner thighs. Stretch your arms forward, then bend your elbows, place your hands on the floor and the backs of the upper arms against the shins.
Snuggle your inner thighs against your sides, and your shins into your armpits, and slide the upper arms down as low onto the shins as possible. Lift up onto the balls of your feet and lean forward even more, taking the weight of your body onto the backs of the upper arms lifting your feet off the floor. In Bakasana you consciously attempt to contract your front torso and round your back completely. If you are ready to go further, squeeze the legs against the arms, press the inner hands firmly to the floor and (with an inhalation) straighten the elbows. Seen from the side the arms are angled slightly forward relative to the floor. The inner knees should be glued to the outer arms, high up near the armpits. Keep the head in a neutral position.