A good tip I got from my buddy (Charles Neil) is to go find some asphalt with some small rocks and pebbles on it, lay down whatever you want to "age" and walk on it. It really makes for a nice, inconsistent pattern that looks far less man made than beating on it usually will.
I have seen many, many artificially aged pieces, and unless the person doing the aging is extremely talented, the dings and dents and such usually take on a distinct pattern, no matter how hard you try not to.
Using the asphalt trick eliminates that, as you have no control over where the pebbles will be.
One table I aged just got left in my shop for a few weeks and used as a bench, and I gave little concern to protecting it from getting marked up. It ended up looking really nice, as there was no pattern and all the marks were from actual use and working on the table.
Another method I used on a small pine sitting bench was to spray adhesive some 60 grit sandpaper to the backs of the legs and the butt of some old jeans and do the same to a pair of gloves. Then I repeatedly sat down and stood up, using my hands to brace myself as I got up and down, and also scooching around a bit while I was sitting, basically so to mimmick the wear and tear from years and years of people using the bench. Then I just used some finer paper to smooth it out a bit and make it look more natural. I spent a good amount of time on it, but it looked incredible when I was finished, like it was truly old with rounded edges where you would touch with your hands and a bit of a dip where you would be sitting. It was actually quite comfortable as well.
Applying a nice dark glaze after aging also adds a nice look to some pieces as well, giving it a sort of old, dirty look.
Aging furniture is very fun, and if done properly, can result in some very nice pieces as well. The best part though, is you don't have to worry about dinging it up during assembly or transport to it's final destination.