Not knowing how deep you already dived into the sea of Krita resources and discovered perhaps interesting ones for you, I guess you can profit from the bundles that I will present below, in the case you don’t already know them.
Here you will find a collection of resources that I believe may help you with your project!
And yes, I am aware that you weren’t looking for brushes, but many of the ones presented here are so-called cheat brushes and roughly cover the subject area you want to work in.
Let us begin with brushes, mainly for foliage and environment:
An absolutely wonderful bundle can be found and downloaded, when you follow my instructions on how to obtain it. And it is not found if you follow the link in the box with picture, that is “only” the resource from which this precious bundle was derived:
A set from iForce73, loved by many:
Currently, I’m working (again) on an improved version of another iForce73 bundle called “Environment Brushes and Forest Vegetation 3”, making it conveniently usable in Krita 5+, but it will take longer as I expected.
With this bundle, you have the option to get her bundle for free via the Google Drive link or purchase it via the link to her Patreon Store if you want to support her (and I assure you, you’d be doing a really good deed). Maybe try it out via the Google link, and if you like it, buy it at a price you set on Patreon:
For this bundle, the same is true as for the one above, if you exchange the Google Drive link against the one from Dropbox which is offered here:
This is also an iForce73 bundle, which I find a little weaker than all the other bundles he offered back then, although the downloads are on a good and relatively stable level:
Here is a bundle for creating maps and environment in bird’s eye view (only the link to itch.io is functional):
For clouds, you may want to try out these bundles:
And now a general purpose bundle instead of specialized bundles.
@FizzyFlower’s “ESSENTIAL” Brushset VERSION 2 is a huge set of brushes for all purposes with 400+ Brushes for Clouds, Paint, Hair, Fur, FX, Foliage, Trees, Leaves, Texture, Smudge, you name it, and very probably you’ll find it in this bundle:
Maybe I’ll add further resources to this posting, but right now I’m out of ideas, and it does not need to wait two more days open and untouched waiting for further ideas.