I just today taught Sadie to "Kiss". Here's how: first you'll want some treats. I prefer small treats (fingernail size) so that the puppy can eat it quickly and you can move on in your training. The treat has to be some thing that the puppy REALLY wants (with any training) so that she WANTS to do the trick to receive it. I tried this trick with one treat and Sadie completely lost interest, so I tried again with a different treat and she did it just fine.
OK, once you have you're treats ready get your puppy. Do a couple basic tricks that your pup all ready knows. once she's concentrating put a treat on your lips, - not in your mouth, just being held there by your lips, you want it sticking out enough for the puppy to grab- and say the command "kiss" and let the puppy know that she can have the treat. do it over and over until you can do it with out the treat there. When I say "Kiss" to Sadie she nudges my lips, your pup can learn to do it too. not all puppies will just nudge though, your puppy may lick you to death when you say kiss! If your pup is a biter i would recommend NOT doing this trick until she stops the biting, I don't want any face injuries. this was a really easy trick for Sadie to learn, it wont be the same with every puppy, be patient. Don't do one thing for too long either, puppies don't have a very long concentration span, do this trick, maybe ten times, then play a game with her for a while. keep it interesting for your puppy.