i forgot a detail, in the top, behind the MESA mountain, i fullfill with Dark Sea Blue...

i tell you cause i say on last step i desaturated blue... i mean this blue sea as i put there as Sky. and then turn into grey

On the lightroom i use mainly contrast, overall color saturation, clarity.

as i desaturate the Blue, the color becomes "grey" and using strong dark vignetting this grey becomes "night".

after i think in a moon... just create 2 circular/radial filter and push exposure to extreme. the first one bigger and more difuse intentisy on the borders, and another inside - smaller and more intense on his end - to emulate a moon and his aurea.

hope i can help

once again i normally adjust mountain size by eye.

at this point i finished the image on light room and export a png to work on colors in lightroom (as a photographer this program is very easy to me). But also you can enhance the colors in this tutorial from @Loopysue on https://rpgmaps.profantasy.com/shore-and-ocean-effects-for-overland-maps-part-1-edge-striping/

i just feel myself more confortable using lightroom as a very long user.

8 - keep displacing houses and adjusting size of the castle and finish sector 2.

9 - start sector 3 (note i have place no land mass on background, just working with images since beginning): place bridge, place tower, place town. 4/ note this side have another wind and smoke go to another direction, its totally optional. Down on sector 3 you can still see Background solid grey 20 as i told. just working with images....

10 - so i finish the mountains on sector 3 given a zig zag movment between sector 1, 2, 3 to make more eye catch.