I'm in a mountain town, and have lost a lot of cats to coyotes, so I gave up on the "just let them roam" theory and only have indoor kitties, who go outside on a lead
I have it set up like you would for a dog, with alittle screw in thing in the center of the yard, with the leed attached to his harness, My dear Giz doesn't know that he can go further then I let him and never tries, the kitten on the other hand, I am still arguing with, he tends to dart out the door still, but then I've only had the baby for two months, and Giz is 4 years old
You can train them not to dart out, it just takes time,