This is how I distress my mantle and it's so easy! How to "distress" painted wood furniture. The technique she uses is a little different than what I've done. Looks easier.with a little less dramatic of an effect.
Painting without sanding - benjamin moore ironclad latex low lustre metal and wood enamel, cheap foam rollers from walmart and cheap foam brushes from hobby lobby. Cut in the trim and angles with the foam brush then roll on the paint with the roller.