Look over the floor area to spot the obvious pathways through the room that would naturally become more worn over time than other areas. While you can distress the floor randomly, working with a traffic flow pattern can reduce the time it takes and make the floor appear worn from use.
Hit, scrape, drag or throw hard-surfaced items onto the floor, using a hammer, chains, a meat tenderizer or any other items, such as loose nails. The purpose is to harm the floor, so hit it hard enough to leave an impression but not so hard that the integrity of the wood is compromised through splits or cracks.
Work evenly around the room, distressing the surface and avoid clumping all your work together. Otherwise, portions of the floor will appear bare and others will look abused.
Rub the scuffed areas of the floor very lightly with sandpaper to wear away splintered areas and smooth out jagged ridges that may be sticking up. Don't sand to smooth the floor; just to make it safe to walk the floor barefoot.
Wet a cloth with cold coffee and rub the cloth over the surface of distressed areas, allowing the brown liquid to stain the wood inside the gouged or nicked areas. Work the coffee into the depressions as well as into naturally abused areas, such as at a front door or in front of a kitchen sink. Allow the coffee to dry.
Apply a coat of clear sealant over the wood floor to finish it according to the directions on the can if you don't want to leave the floor as bare wood. Allow the topcoat to dry thoroughly for at least a day before you walk on the finished distressed oak floor.