We don't use them much either - we prefer love/praise or a little bit of play to 'celebrate' the behaviour. But now, at 15 weeks, we're asking for a slightly longer attention span. Bo is very food-driven, not very prey-driven, and the lessons we're using it for are for instance 'heel' and 'follow'. But 'follow' doesn't work very well if we need to stop so she can crunch on something, or if I need to use two hands to break a treat into smaller sections.
Pup doesn't have very much interest in fruit/veggies as treats; she doesn't mind them if they're mixed in with her food. She likes the occasional blackberry or piece of plum, but it doesn't motivate her to the point of strong focus like the salmon did. Maybe it's an aquired taste? (Or I just have a rags to riches pup?)
The cheese sounds like a good 'special' treat. I'll definitely give that a try.
Keep 'm coming!