Worldbuilding

Most of my fictional cultures in Matters of Honor are made interesting by having them take on the **surface styles ** of one ancient culture (names, looks, architecture, all mildly vandalized to make it more fun/fictional) but they tend to have deeper similarities to an entirely different culture. For example, Breccians are vaguely Germanic in style, but they have a culture of paranoia and cultishness, debased royalty, and organized crime intertwined with government more reminiscent of modern day Russia. I didn't come up with that process step a priori, I kind of noticed I was doing it and went back and did it on purpose. I think I do my best work this way, playing around and only later formalizing my process. It just takes ages, which is fine when you're between groups.

Recently I figured out that the problem I'm having with Zerzuran culture was that there is no such definite juxtaposition. There are cool tidbits, but there is not much dynamism. I struck upon the idea of refining their surface styles as more firmly Persian (instead of a mishmash of middle eastern) while drawing out deeper similarities to a wild west American thing, specifically drawing on spaghetti westerns and the interplay between encroaching city life against a fading frontier spirit. They already had spice rangers to fill the niche of heroic cowboys, after all.

How do you write your own original cultures? Is there a better way than carefully laundering things you've stolen from real human societies?