We built this simple rustic bench for our mudroom, which is the main entry to our house, since no one uses the front door. For the complete instructions on building the bench itself (sorry no photos but feel free to comment with questions!) visit my wife's blog, http://thekieffercollective.com/2013/09/08/bench-fest/. This Instructable is just about the antique finish she did for it.
Since nothing screams "newly built!" like sharp corners and edges, the first step is to soften all those hard lines. We're trying to make the wood look older than it is, and anyone who's moved a few times knows that the corners are the first things to get dinged up. So start by taking a hammer and hitting the corners and edges of the seat and legs. Then, I took the hammer and dropped it from about 18" above the seat, to add in gouges and nicks to the seat top. You can also take the claw end of the hammer and drag it along the surface for longer scrapes and scratches. Since this bench was made from pine lumber, the wood was soft enough that it didn't take much force to soften the edges and corners, but if you're working with a hardwood like cherry or oak, then you'll need to apply a little more force.