Keep like items together -- clothes, toys, DVDs -- as you gather them for the sale so they're easier to organize.
Have a multifamily yard sale (better selection is likely to attract more customers).
Ask a local charity to pick up what you don't sell. Most will do it for free.
Place your goods on tables arranged in a U-shape formation. The layout will keep shoppers moving instead of dawdling.
Display small items in a bin labeled "Buy two, get one free." Less time spent pricing for you -- and there's a good chance it'll lure customers into impulse buying!
Slash prices midway through the day to boost lagging sales.