You don't need to be flashing your passport cover AS a passport cover. It can--and probably should--be nice and nondescript. Minimal exterior stitching and plenty of space inside for all your time out of the country.

Laser cut from Horween horsefront, hand stitched with five interior credit card slots, a pouch behind the cc slots for cash, a slip-in/slip-out passport slot (with space for a second passport), and space behind the passport(s) for paperwork.