Playing as a Wraith in a custom faction, and using custom units.
But i hate that i have to either have goofy looking troops (most wraith head/skin combos look rather weird to me), or keep clicking on the redo button for minutes, if not more, to get some though/fierce looking warriors to my armies.
So ability to design how your units look, on top of their gear/hair, would be welcome, including how tall/bulky they are.
Yeah, this is hardly very high priority thing, but if it could be done without too much trouble, it would be a nice addition to the games customization options.