When I run out of dog training ideas I borrow horse training ideas. It's amazing how many concepts transfer between species, LOL. The ones for training trail horses tend to be especially useful. They fall into two basic categories:
Getting used to scary objects
Improving coordination and footwork
Horses are hyper-aware of their environment and treat any change with deepest suspicion. A new rock showing up at the edge of a familiar trail can trigger five minutes of balking, snorting, and intense scrutiny. (Horse logic: "Rocks don't walk around by themselves. How did this one get here? Is it really a rock? Is it dangerous? If it is a rock, what put it here? Is the thing that put the rock here dangerous? Is it still here?") So, a lot of trail horse training involves exposing the horse to all kinds of random stuff that might show up next to a path one day. Baby strollers, swinging real estate signs, people opening umbrellas, flapping shopping bags, people wearing funny hats, little kids with helium balloons, bicycles, skateboards, inflatable snowmen... The list is infinite.
What's funny is that I've had dogs spook at the same kinds of items that have scared my horses. A couple days ago my boy Galen got very jittery at a newly opened trench for a neighbor's lawn sprinkler. We had to carefully inspect all the pipes, dirt piles, and sprinkler heads before he would relax. (Then today he proudly showed it to Pogo, who was completely unimpressed.) Galen also got very skittish when he saw two ladies carrying beach chairs, when he saw his first baby stroller, and when he saw a full sized clothing display mannequin. I'm now trying to make up for lost covid time by showing him as much stuff as I can and taking him to as many places as I can.
Footwork and being used to walking in a variety of surfaces is also very important to a trail horse. Tripping on fallen tree limbs or wiping out on concrete will really ruin a nice afternoon out. Therefore, horse trainers make trail horses practice walking over all sorts of obstacles: poles laid in various patterns, mud puddles, tarps, tires, and even mattresses.
Galen, as he matures, has been learning and practicing similar skills. Stairs were a huge deal for him. His first exposure to a hardwood floor shocked him. (No traction.) This week he got his first romp in wet, unmowed crabgrass and promptly did a face plant. He still hasn't got full confidence jumping in and out of my car; we will be practicing more.