honestly, backgrounds, landscapes and all that stuff is the most enjoyable part of drawing for me so i'm gonna share how i do it
if i do a photo study, i try to make the whole piece less detailed and more based on recreating the colours and shapes that would make up the general vibe i'm aiming for rather than copying everything that is visible in the photo
(or even if i'm not doing a photo study and try to draw from my imagination, it's better to operate with simple shapes and then add details gradually)
so, when it comes to planning out the whole background, i usually focus on those simple shapes and skip the sketch phase cause it actually makes it more difficult (at least for me)
SOMETIMES though, i do a sketch but only when i have something else in mind and not only the basic landscape, like adding some characters or animals or other important objects
...but more often than not i add them later cause my process of thinking when drawing is really chaotic so i usually decide to add something in the middle of creating (like here) if a random idea suddenly pops up in my mind lmao
after drawing those basic shapes i add more and more details, shadows, lighting, etc... at this point i merge all of the layers if i decided to start with a sketch; if not - i draw everything on only one layer from the very beginning (but it's just my personal preference and also a matter of habit ig)
i like to make some aspects of my backgrounds more vibrant and saturated so that they can stand out more and the whole background isn't that dull; i usually do it with clouds, lighting or smaller details, like here
also! a little tip on blending colours and drawing a basic lighting from me - if you use this more saturated colour for, let's say clouds, blend it a little with the base colour of any object you want to put lighting on. the new colour can be used like that, it's slightly less saturated and fits better
i've probably mentioned that some time ago but i play A LOT with saturation and darkness of the colours during my process of creating cause i feel like the colours i pick at the very beginning are a bit too dim and muted to my liking and making them more vibrant makes the whole piece more interesting imo
and that's it! it's really not that complicated, mainly just playing with colours and their saturation and depth;>