I'm a fan of contrast.
Slick chunk of metal with a delicate design etched within, wicked spikes fastened to precious pearls, sparkly Swarovski capping a spent .22 - you get the idea.
Something that's always struck me is the idea to contrast the Frontier Days of 1800's western territory exploration (admittedly, inspired in part, by Seth Grahame-Smith's deeply philosophical Abraham Lincoln - Vampire Hunter, especially the line "where men were few and arrows flew") with the future. Cyborgs with lassos, dusty metal-jointed tumbleweeds - that sort of thing.
A lot of my work has a taste of this "Future Cowboy" image, but I haven't...