Here are a great pair of videos from Logan Hursh of Midwest Twisters.

These two videos are great examples of athletes working the set and subsequent shape recovery for quality flipping skills. The first piece is making sure that the athlete opens up the upper back and shoulders to lead the flip rotation. Then they must use their tension to stay connected and essentially pull the feet with their backwards flip momentum. Following the initiation of the rotation and lift of the full body, the athletes work to snap the lower half over the top of the flip to accelerate the flip action and create the quality layouts tension. These gymnasts do a wonderful job of showing a great set and body tension throughout.

Hope these can help you and your gymnasts create their Best Darn Gymnastics!