Novel things are fun
Safely introduce your puppy’s senses to the widest range of stimulus you can come up with. The puppy is rewarded for being interested and curious but not over stimulated or fearful. The more novel things they learn about, the more they will take in stride novel things they have never learned about.
Watch your puppy carefully for signs of arousal and manage the training opportunity carefully so as not to over do it. At the same time, keep calm and in control of your emotions if you misjudge something and over face your puppy.
As your puppy becomes more relaxed and comfortable in these settings, ask your dog to do simple jobs for you while there. This will teach your dog to generalize behaviors they already know, and will help build their ability to work in distracting situations.
Some important tips:
1) Be cognizant of developmental fear periods and keep scary things short, far away and soft to begin with. Work on other tasks during fear periods when the puppy is not predisposed to be unnaturally cautious. Make a note of what was an issue and go back and work it again in a few weeks but don’t assume the puppy will “grow out of it” or “get over it” - make sure they do - with careful training.
2) Manage the training carefully and physically remove your puppy from overly stressful situations.
3) Don’t hesitate to tell people exactly how to interact with your puppy (or not to interact at all) and insist upon it. Kind-hearted people generally put too much pressure on a puppy to engage with them because they like and are empathetic to dogs.
Here are some ideas for where to find novel things to introduce.
1. noisy places: train yards, firehouses, small airports, boat yards, ferry loading area, docks, any place where there’s heavy road equipment running or building construction.
2. lots of people and activity: university district, sidewalks, coffee shops, street fairs, farmers market, skateboard parks, outside grocery stores, hardware stores, retirement villages, bus stops, outlet malls, libraries ...
3. lots of smells and terrain: Parks, trails, woods, big open spaces, rough terrain, grassy fields, gravel roads, sidewalk grates, walking path bridges, open-backed staircases, manhole covers, storm drains, wobble boards, cavaletti...
4. lots of dogs and dog-energy: dog shows (agility, lure coursing, 4-H..)