What are some tips that will help me ??
I used to be able to do that when I did gymnastics! It's pretty easy to be fair, just do your normal cartwheel but as you get half the way around sort of twist your body around 90 degrees.. Land and do your little square and both hands in the air.. Trick is, is to squat at the end and put both hands in their air, girls it's both lads it's just the one, that will make it look a lot better and if your bring judged that is what they will judge you on more.. But I hope that helps :-)
For my gymnastics team, be practiced roundoffs by doing regular cartwheels and pushing off with our hands. After mastering that, try to get the form right. When you are running and ready to do your roundoff, extend your body (be sure to point your toes) and then springing off with your hands. Twist your body in the air and try to land on both feet. It takes a lot of practice. I'm still having trouble with my roundoffs.
PRATICE! PRATICE! PRATICE!