Teaching a puppy to target the palm is one of the basic behaviours I always include in my puppy visits. It's a very easy behaviour to teach and to use. The response I often get from clients is what is it and why do I have to do it? Most people haven't heard of targeting and aren't aware of how valuable a behaviour it can be. From playful puppy to aggressive adult, this little trick has many functions.

The basic idea is for the puppy to touch the palm of your hand with his nose - that's it. The applications for this are numerous. 
For dogs who are anxious or stressed it provides a focal point. On crowded city streets, it brings the dog closer to you so can maneuver around obstacles. 
If you need to redirect your puppy or dog, you can cue "touch" which gives them something to do as opposed to yelling at them to stop. Is the puppy or dog on the couch? Cue "touch" and reward when he jumps off. No need to yell (we won't talk about management here!)
Bring dogs back into heel position after a "go sniff" with "touch" or use as a secondary cue for recall.

Both my dogs are trained to come and touch my palm, no matter where they are or what they are doing. They don't have to know it's a recall :) My older dog stopped responding to "come" a few years ago but still responds beautifully to "touch!". The younger one knows both - so I always have something to fall back on if one fails.
Use this to prevent children from inappropriately grabbing the dog or for children who are anxious around the dog. This is a safe way to say hi.
When outside, redirect from a person, object or animal, with "touch". 
When greeting new people ask them to put out their hand and cue "touch".  For a dog who lacks confidence, this helps prevent inappropriate human greetings (a pat over the head). 

For a dog who reacts to stimuli outdoors, cue "touch" to turn the head away from the trigger. Plans to do Agility with your dog? Hand targeting directs the dog though the course.

The list goes on and on.

How do you teach it? First determine what the signal will look like. If you use a flat open palm for stay I suggest using two fingers as in a Peace sign. I like to teach the dog to target the hand on the side that he heels on.
  1. Have your treats handy. Be prepared to mark with either a clicker or "yes".When teaching anything new you always make it easy for the dog to be successful. 
  2. Place your hand just in front of the dog's nose so he has no choice but to investigate. Mark and treat. 
  3. Remove your hand to either behind your back or rest on your belly. 
  4. Present it again and repeat the sequence 3-5 times.
  5. When your dog is getting the hang of it begin to move your hand slightly to the left or right, repeating as above.
  6. Only add the cue "touch" when it is obvious that he is moving to touch your hand - and you are willing to bet $50.00 he will do it!
  7. Gradually increase the distance he has to go in order to touch your palm or fingers.
  8. When you practice outside or any new environment, begin at the first step
If your dog is reluctant to investigate, mark and treat when he looks at or sniffs in the direction of your palm and gradually build to an actual touch. 
Make sure you are not cheating! It won't work if you move your hand towards the dog. Your hand must remain stationary and the dog has to come to you!

Once your dog gets the hang of it you will be surprised at how useful it is!