I will haggle briefly and then walk. It's a buyer's market. I figure out what I want to pay for an item and offer a little bit lower than that, then come up to the price I've set in my mind. Usually works well.

Often I'll ask the price of an item (having an idea what the going rate is already) and if they quote me an outrageously high price then I know it's not a vendor I want to deal with and walk. Any attempts at hustling will also cause me to walk away. If the vendor offers a fair price for the item, s/he'll often get a little extra from me just for having good business practices.