It started with the youngest one also jumping up unprompted (with claws yes). I thought it would be kinda cool to discourage unprompted behaviour and encourage it with a command instead.

Took about a week or so? I used treats and tapped my shoulder, which is the signal to jump on.

Now, they don't need treats and just enjoy hanging out on my shoulder. The oldest one even learned to ask for it (she usually doesn't vocalize much, so when she does, its to jump onto my shoulder). She really enjoys chilling on my shoulder while I'm cooking