I'd just suggest walking around your town for a couple of days and seeing where you naturally walk, then put your paths there!
Then expand from there to makesmallwalkways to pwps and such!
I wanted to use a path that has like 10 pieces, but I took the generic non-border/corner piece and placed it around town guessing where id want it generally and then reorganized as I saw fit, imagining how it would look completed. It's easier than laying out something more elaborate. you dont even need to pick a path just lay out a blank custom design, but the path will probably help you visualize it better.
Perhaps draw the map out your town and draw line paths for a basic idea and see if you can actually work it out in game.
I also used my bridges (which I liked the placement of) as points where I knew I wanted the path to lead up to/from.
It may be hard if you have villager houses placed randomly everywhere, and you aren't satisfied with the positioning and you'd have wanted paths through them. I luckily had a somewhat good way around all the villagers that moved in to my town.