I've stumbled across a lot of moons and said to myself "if I wasn't wandering around this area, I never would have found this one."

I find myself stumbling across well-hidden moons frequently, but I think that once I get to the point where I've found 750-800 of them, they're going to start getting really hard to find. Thankfully, you can use Amiibos to help you sniff out their general locations.