I just really struggle to coordinate this kind of conditioning. But I know I haven't proofed my dog's sit and stay enough. I watch kikopup do it so very well and I get all excited and then I never get round to doing it because I find it boring. And think it's boring for the dog and I'm way too soft in that regard.
I'll set myself a goal to proof that sit and stay after our foster dog leaves and before the next one arrives. I might work on some other 'tricks' she can do when greeting people. Just sitting won't stop her urge to lick.