This trick can be taught with any toy or item and could turn out to be very useful if you lost something. Besides the practical usefulness of this trick, this is a really fun game to play with your dog! Have your dog go out of the room and sit, then hide the object somewhere in the next room. The object could be anything: one of his toys, an article of clothing, but make sure he knows what he's searching for. For a more advanced performance, hide something with a less noticeable scent, such as the tv remote or a set of keys.
Step 1: Have your dog sit.
Step 2: Hold up an object that he is familiar with (he knows its name) and let him smell it.
Step 3: Place the object under something obvious (like a towel), and say "find it." You might add the name of the object if it doesn't do it quickly ("find it" bunny). Click and treat when he touches the object.
Step 4: Repeat several times, but each time you repeat move the object to a different location, getting progressively more difficult. Click and treat each time.
Step 5: Let him smell and then hide other objects that he is not familiar with and give the "find it" command.
When I first taught this trick, I was using an old Atlanta Braves hat that I used to wear. Because the hat had a lot of my smell on it, it was really easy for Caspian to pick up on. It started out basically by accident, I hadn't planned on teaching him this trick. I was just playing around with the old hat, playing keep away, putting it underneath things for him to dig it out. I had him go out of the room, and I stuck it partially underneath the rug, then called him. He sniffed around a few seconds before finding it. Although I had stumbled upon this trick by accident, I got my clicker and started rewarding him for finding the hat. Because he had learned the term find it, in relation to finding things with my scent on it, when I lost a set of car keys in the backyard one day, I told Caspian to "find it." Although he didn't know what he was looking for, he went to the thing that had our scent on it. In just a few minutes, he had found my keys.
My dog doesn't understand what I want him to do. Some dogs have great noses; others don't. But your dog doesn't have to be a bloodhound to learn this trick. When starting out, make sure the toy you use to hide is one he really likes. Also make sure he knows its name. Start out easy; you may not want to even hide it starting out. Put it in plain sight and encourage your dog to touch it. After that, then you can start to hide the toy in progressively more difficult spaces.
Tip: "Use the same terms each time! In other words, don't tell your dog to "Find it," while still using "Get it," "Where is it?" and "Search" intermittently. Consistency is the key!"