i agree with everything everyone has said above!!
inspo is everywhere and i think simply being on the lookout for it is the key - here on the map thread or the other inspo/post your town threads (you can watch them for updates and get continuous inspo w no work, which i love lmfaooo), or on twitter by following people w the style you like, or the same on youtube, AS WELL as engaging with media (photos, movies, etc) of things that fit the vibe you want to cultivate or that you enjoy. save these things to a file or a bookmark folder or what have you, so you can easily look back at them.
additionally though, i want to say in the planning phase, i kept being bogged down with the ideas of things, getting carried away terraforming or whatever - before i started to require myself to draw and plan everything out by hand, in small sections (just the museum entrance or just a valley). i know this method really depends on how you work best, but i have found it so helpful to visualize and mess with design of things before trying to implement it and doing it by hand is very soothing as well. i've found a sort of comforting meditation in it. not to the level of a bulletjournal, but just a design guide like so:
best of luck, regardless. be sure to share your work with us on the forums for feedback and fellowship!
