Your Main Variables = Price, Location, Condition, Exposure (marketing)
Location you can't change. Condition is probably good since your house is fairly new.
And the fact that your original price is so close to your current price as a short sale makes me think your price isn't low enough. Short sales are worth less for 2 reasons: 1) The buyer expects (and deserves) a discount just for having to deal with the short sale. 2) Short sellers don't get to walk away with anything anyways so they have little motivation to keep the price high.
90% of marketing is just having your home on the MLS. If your home is on the MLS, there are little things you/your agent can do, but they won't likely be the catalyst that sells the house. If your home isn't in the MLS, get an agent to put it in there ASAP.
Like Deva said below, you may want to consider renting out your home since rentals are in high demand in many areas right now.