Teaching a dog to target is one of the easiest skills for them to learn. You can teach a dog to target with any part of their body. Nose targeting is usually the easiest since dogs are inclined to sniff things. But you can also teach them to target using their paws, or putting other parts of their body on something. I taught my border collie to target with his chin. He will rest his chin in my palm, on my leg or on an object. I didn’t have any particular reason for it, sometimes I just try to see what behaviors I can teach my dogs. They don’t mind since I use reward-based training methods and suspect they think they live with a fool.
“You mean all I need to do is rest my head in your hand? You’ll give me cheese? You gotta be kidding me! Hey Rex you gotta see this. Watch me get cheese!”
I use targeting for a variety of reasons with fearful dogs. This video shows a few of those reasons.