There's lots of different ways:
One of my favorites is to strap the hoop to the handlebars and let the other side rest on my bike box held on my rear carrier rack. I ride in the middle, kind of in hooping position. The hoop moves with movements of steering a little and so is not attached in the back to allow for this.

Otherwise I go over the shoulder and strap on the hoop so it won't fall off and onto my arms while riding.

For burning man I made a special rack kind of like a sissy bar on the back of my bike because I'm usually carrying about 4 hoops of different flavors. The hoops are suspended high in the back giving me a hoop halo effect as I approach while a saucy Barbie pole dances on the pink fur upright sections of the hoop rack visible from the back.