8O Peanut butter first, then crunch up a pup biscuit, then a bit of plain organic yogurt, then a few Cheerios, then top it off w/more peanut butter to seal it--then I freeze it! Bibby LOVES it. (Man, he makes the most disgusting sucking noises...lol)
Cassius is pretty easy, we fill about 2/3 with kibble and then wet dog food to the top, stick in a small treat and freeze. Haven't heard a complaint yet. Then again we only give it when he is being crated and as soon as the baggy comes out of the freezer he's halfway to his crate looking for it.
I love this topic though, when we figure out what works and doesn't with our pup we'll try some more ideas.