Extending the search area
You can extend the search area by spreading out the objects your dog is searching. Because your dog is now expecting to find treats on the objects, we use the objects to get your dog to move around a bigger search area by placing the objects further apart. Spread the objects out gradually. If you make it too hard too quickly you might lose your dog.
Put less treats out there… your dog should continue to search every object, but now they will just find treats on some of them. Again, reduce the treats gradually because they are what is motivating your dog. An advanced sniffer dog will search for a long time for one treat. A novice sniffer dog will give up if it is too hard. Keep your dog in the game by keeping their motivation up with enough treats for their skill level.
More/different objects to search
You can make this more challenging and interesting by adding more random items in your search for your dog to search. You can put less of your original search items (like the cones I used) and more other random household objects. For beginners, use clean objects that don’t have a strong odour. Make sure the objects you choose are safe and unlikely to scare your dog when they investigate by sniffing (i.e. by the object falling over for example).
Elevation
Elevation in nose work is where we start to hide the treats higher off the ground. This teaches your dog to search different levels and to lift their noses off the ground as part of their searching. Again, don’t make this too hard too quickly. At this level you should aim for your dog to be able to reach their own treat so they can continue to self-reward. Be careful also that you don’t accidentally encourage bad manners here by teaching your dog to take food off tables etc.