Tag and label every item the night before in order to reduce the amount of work you have to do the day of the sale. This is a good time to create a pricing list, in case tags or labels fall off of items.
Price accordingly; yard sales shoppers are there to find thrifty goods, so expect anywhere from 45 to 75% depreciation for most of your items.
The morning of the sale, use your pricing list to take inventory of each item on display, and after the sale has ended, take into account how many items you have left, and their price, to see how you came out.
Label and Take Inventory