Hoop Tricks; Duck In.
Start by spinning your hula hoop around your body, doing a body orbit as I believe it is called. Bring the hoop behind your back and then bend over bringing your chest to the ground. At the same time your hoop is going to start rotating around your thumb that is pointed towards the sky. When the hoop twirls over your back and you can see the open space it creates, bend up into the hoop and use your hand to give it s whirl and keep the momentum going.
Viola, you just ducked in!