How do I do this?

I started out with one of them silicone ones, it had a big base ring that a plastic strap went thru the cage and around the base ring to hold it together. it was an... interesting concept, but dint really work well. the non rigid base ring made slipping out just a matter of (not much) time. The cage shape was oddly long on the front so my penis could go all the way up to the end. all in all... I wouldn't recommend that particular style.