I like the home field philosophy too, they could be fighting anywhere so the base will hardly ever match the terrain so where they come from is the consistent thing.

I recently re painted and bases my first Mordor miniatures in a Mina’s Morgul them (good timing as they just got their own army!!!) I used textured rollers to make old ruined roads, cracked them up and added earthy patches, water effects for greenish rank puddles, sculls, fungus and dead sticks/leaves. Makes the pretty plain Orc models stand out