Kai - Treats. He'll work for any treat but he gets most excited with cheese. I use cheese for agility training since he speeds up most when I use it.

Kaedyn - Treats and praise. He'd rather get the treat but he responds very well with praise alone too.

Kuri - Fetch, frisbee, tug, treat. He prefers the frisbee and tug over the fetch and treat but he'll work for any of them.