Mine is almost three now. I trained mine when he was young with treats. I use normal human nail clippers. I cut as needed since he'll sometimes use scratching posts more or less often, usually once every 2-3 weeks. But since he likes jumping on my lap while I'm at the desk, as soon as I can feel his claws sharp, I'll cut them. He plays a lot with my dog too, so I don't want the claws getting deep into my pup.

I flip him on his back, on my lap at the desk, and just quickly cut the nails, telling him, 'Good Kitty' (which he's associated with treats by now), and then always make sure to give him a lot of treats and love after. He definitely prefers getting his nails clipped on my lap at the desk. If it's in other places, he'll squirm or run.

Have you trained yours to associate a positive saying (like, 'Good Kitty') with treats?