Run dusty dishes and filmy glassware through the dishwasher. A quick spritz of automotive vinyl protectant makes small appliances and plastic items shine like new. Clean, fresh-smelling clothing hung on hangers commands a higher price than stained and rumpled items tossed into boxes. Pay attention to packaging. Plastic food storage bags group children's game pieces, display jewelry, and hold hardware bits and pieces.
Experience comes down in favor of pricing every item.
Yes, haggling is part of the yard sale scene, but for those with shyer natures, a price sticker saves a lot of energy. Buyers are more apt to buy when they know the price is in their ballpark. As for you, the middle of a crowded carport is no place to have to come up with a price for every spoon and trivet. Use masking tape or small adhesive stickers to label your wares. Bundling is an old retailer's trick, and one well suited to the yard-sale seller.