I find that the most satisfying and safe way to practice Reverse Warrior is to focus on the side bend, only allowing slight extension in the upper spine. With a few conscious and powerful breaths directed to that side body opening can be a great experience of liberation.
Pay attention and listen to your body, move slowly and with intention.
Come to Virahabdrasana II [Warrior Two]. Step your feet wide apart. Front foot pointing forward, back foot pointing out. Bend the front knee so that is is directly over the ankle or just behind. Open the hips and shoulders to left. Lift arms parallel to the floor. Actively press down through both feet.
With an inhale lengthen your spine, exhale reach your left hand back to your hip or thigh. Gazing at your right hand, spin the palm to face the sky, reach the right arm up and over your head. Your fingertips reaching toward the wall behind you.
Pull your low ribs into your body and let your sacrum have some weight. Even as you reach the front hand back try to lift the front ribs up diagonally.
Take a few deep breaths here. Finding gratitude for the body and breath.
Inhale your torso back up, exhale lower your arms.
Now try the other side.