Fixing an overseasoned dish

Well tonight I did it, added too much salt to dinner. Made steak tacos, and the taco powder was too salty. One old tip is add a potato, which works with soups, but didn't with this. I added some sour cream, diluted it with salsa, and not much help. So after I get home I ask a chef (gotta love twitter), and they suggest adding sugar to balance the flavors, which makes sense to me. So my question to you is what are your tips?