Grip the rings, tuck your knees to your chest and pull your hips up to an inverted postion.
Depress and protract your scapula. Arms are straight, brace your core, keep your legs tight.
To progress on from our initial tuck position, open your hips to form 90 degrees with your body.
Maintain this position, and descend with control. If you find this to challenging, descrease the intensity by tucked your knees in. Don't allow your back to arch.
Rotate the rings so your palms are facing away from you, and lower your hips so they are level with your shoulders. Your back should be flat. Be sure to maintain tension and Scapula Protraction throughout.
Hold for time, stopping before form breaks down. Pull yourself smoothly back through the rings, by tucking your knees tightly and by further protracting your scapula.
It's a good idea to film yourself, or have somebody spot you, to check hip position as you develop your spatial awareness in the back lever position.