Concept designs for axiverse

I guess Airbrush is most suitable to me due to its attributes of being opaque and smooth, it is something like a mix between oil and watercolor and thus I will treat it as such.

I've written a tutorial of my approach (unfortunately in German :0).
"Be like a sponge—suck up everything you can lay your eyes on. Look for the unusual, the common, characters, situations, compositions, attitudes study shapes, features,
personalities, activities, details, etc." - Walt Stanchfield
The first pages of my new "spongebook":
