I was thinking how cool it would be if the type fonts for the klingon faction could be in a Klingonese sort've style. Maybe have some of the letters be similar to Klingon letters but make it seem very rune like.
I was also thinking that the Hud for the Klingon side could be made to appear more Klingon like. For example, pop up windows could have a metal outline with different lights and add ons. Just make the Hud seem more gritty and militaristic and not so Red.
It would be cool actually when you get promoted, Jm'pok says it in Klingon. WIth translation of course.