Vrksasana

tree pose

From tadasana, bring the sit bones slightly towards the back of the knees to create space in the lower back, feel how the lower abdominal muscles tighten.
Shift the weight to the left foot & spread the toes.
Strengthen the left leg, pull the kneecap and push firmly into the mat with the whole foot.
Lift the right foot and place it with the sole against the ankle, toes in the mat OR against the lower leg OR against the inside of the left thigh, with the heel as close to the crotch as possible. But NEVER against the knee.
Open the right knee to the right but keep the hips parallel to the front of the mat.
Push with the right foot into the left leg and with the left leg into the right foot, so the force goes in both directions.
The sternum comes forward and up slightly, but keep the sit bones slightly towards the mat, so there is no hollow back.
Place the hand palms together in front of your sternum OR raise them with your arms extended, palms together, at shoulder width or slightly wider.
Gaze is forward.

Inhale: create length between the heel and the sit bones & the sit bones and the crown of the head. When arms are straight also between the shoulders and the fingertips.

One of the variations mentioned, possibly a hand can be placed on the wall to help with balance.