The more you ignore them, the more they want attention from you.

If they're standoffish but still somewhat curious, you can crouch down from a safe distance away (typically about 6-8 feet, if you can get that close), reach out one hand, and stick out your index finger, pointing slightly upward (at about the angle a cat's nose would typically be if it were coming over to nuzzle you). The cat may trot over to boop your finger with its nose. This is not an invitation to pick it up or even pet it, but it's a good first step, and lets the cat know not to be afraid of you.

If you can do a convincing kitten "mew" and trill, it might put the cat at ease. Unless the cat is an anti-natalist, in which case it may try to rip your face off. Or if you accidentally say something incredibly offensive in Cat. Use your discretion, and try not to translate H.P. Lovecraft's cat's name into Cat, on purpose or otherwise.

If a cat trusts you enough to get close (e.g., the finger-to-nose thing), you might be able to get it to eat something like a Churu -- specifically, something gel-like and stinky. Slow, deliberate movements are the key. Cats are almost as jumpy as cops.

You can also try slowly doing the face at the cat. If it slow-blinks back, it trusts you. If it cocks an ear and turns away, it thinks you're a dingus, but at least you're harmless.

Thank you for coming to my talk.