Children are smarter than any of us. Know how I know that? I don’t know one child with a full time job and children. – Bill Hicks
As usual, start with an APK Warm-Up, #2.
This is a great video that shows some good basic tumbling exercises: http://www.catalystathletics.com/media/video/video.php?videoID=22
These drills are meant to build “air-awareness” which is proprioception and the ability to recognize where your body is in space when it’s off the ground or spinning and rotating. Watch the video and perform the movements.
If you’re experienced in tumbling or acrobatics, spend some time drilling some moves or combos. Butterfly kicks and butterfly twists are a good place to start into acrobatic movement.