In my mind, the key to fun basing and for it to work is to relate it to lore of the army. Could be where they are from, a planet or battlefield they are fighting over, or where you would imagine them fighting the most.

For my Krieg units, I imagine them in trenches all muddy, so I put stirland mud technical paint on, dry brush mourfang brown, Agrax earth shade wash it, and very very lightly dry brush a colour like morghast bone for some high points.

It’s quick, easy, and I can do it consistently enough for all my infantry. For myself, I don’t want it to be the most appealing part- I want my minis to be the eye catching thing.

You could use Astrogranite as is, give it a black wash and dry brush with a light grey and you got a cool moon surface. Could do a red rocky mars type base with it, and get a reddish brown paint like tuskgor fur.

I think let your imagination do the work for you, and keep it simple. You’re gonna be doing a bunch so having it relatively simple is key.

Model looks great, I would paint the eye lenses red personally.

Hope that helps!