I don't know if you have already decided on dates yet...but around here (Upstate NY) eveyone does Friday and Sat. - or only Sat. No one does Sunday sales anymore. Be specific in your ad - I have to pick and choose between sales, so I will be more likely to go to one that says 'baby clothes', 'books' or whatever, rather than one that just says 'garage sale'. If you have antiques and/or collectibles, list them in the ad. They catch the eye of collectors.
Price low, especially on clothes. I refuse to pay more than $.50 per item of children's clothing, except for rare exceptions. I hate going to a garage sale and finding $2 on a kids shirt - a waste of my time to stop, because I can buy a shirt in the store for that on sale. JMO - your area might be different if people are willing to pay more.
Bowling balls rarely sell - anything that is too dated (clothes, furniture). If I have things that probably won't sell, but I don't want to add them to the landfill, I will put them in a free box. People have taken broken appliances, torn clothing, etc. this way. At least it doesn't go to waste. People can use the parts or the fabric for something else (don't put the free box at the end of the driveway where people will stop first - we have had people check out the free box, find things, then leave!).
I usually don't buy food unless it's a neighborhood type sale, where I have been there a long time (btw, these always catch my eye in the paper and I make a point to hit them), it's a really hot day, or it's kids selling lemonade. I also have been known to buy an occasional baked good just because it looks good
but I don't think I have ever bought candy. I would stick to baked goods, hot dogs, soda - things you can reasonably eat yourself if they don't sell.
HTH - good luck.
jodi
Oh yeah, put signs all over. I had heard once to plan on how big to make your signs - then make them twice as big. Be specific with arrows/directions- I hate searching for a garage sale. And be sure to take them down after the sale!