Do a little research on the sales in the paper first. If the sale is being held in an upscale area, chances are good that they may have some antiques or other valuable items that they want to get rid of. Don't underestimate other sales though, you never know what people might have. Some sales may turn out to be bust while others that didn't sound good in the paper may be a boon.
Moving sales are sometimes the best sales since the seller is more motivated to get rid of their items or they may be desperate to get rid of some things that they can't take with them.
Get there early! The early bird gets the worm. Many dealers and eBayers get to the sales they have scoped out to be the best ones early, sometimes an hour before the sale is supposed to start. They do this not only to be the first ones in to buy, but to also potentially look at or even make a deal before the sale even starts. They are also hoping that, by getting there early, the sale will be already set up and ready for buyers to look at, then they can say oops, I got here early and then the seller will let them in early. This is one way the serious "dealers" get the real deals. They get there before everyone else. This is also how dealers get the great prices, since so often, the seller has no idea what something is worth, the dealer who gets there first can offer a tiny fraction of the price, make it sound good and then traipse off with it without anyone else ever knowing it was available. The seller probably even thinks they got a good price.
To many people who have had multiple garage sales, the early bird dealers are known as "vultures". It's a good name for them too, since they are experts at not only taking advantage of the timing, but also their own expertise and the sellers lack of expertise. When you get to a sale a few minutes early and you see other, serious looking people there, standing around and waiting, there's a good chance they are "vultures" and you have stumbled upon a potentially great sale. Many sellers find vultures annoying or opportunistic, so I don't recommend using this strategy. If you do decide to try being a vulture, make sure to respect the sellers wishes. If a garage sale ad says, "no early birds", they mean it. Respect their wishes. Just being nice is underrated, you're more likely to get a great deal by being nice and friendly than being underhanded or aggressive.
Don't underestimate what you can get when getting there later in the day. When the sale is about to close or even when the seller is cleaning up and putting things away, you may just find something other people have missed and get a great deal for it.
Timing is important, don't forget to schedule and prioritize the sales you plan to attend. They often start at different times, so you can hit one that starts at 8, right when it starts. Then you can hit another right afterwards that starts at 8:30.
Did something catch your eye earlier in the day but you didn't buy it when you had the chance? Maybe it's still there! Go back later in the day to see something you regret not buying. Late in the day, sellers may be even more willing to negotiate.
One of the most important tips is to have cash with you. Most sellers, unless they know you already, will absolutely not accept checks at a garage sale. Make sure to have enough cash on you, so you can buy what you want or make an offer right then and there. Also, don't show your money. If you have a ten dollar bill in your hand and you offer the seller $3 for something, this makes it less likely they will take a lower offer. Of course, don't forget to haggle, this is the point of garage sales!
High tail it out of any sales where the seller is 'firm' on all their items or is asking close to retail prices. Also, try to weed out the sales by the same people that have never ending, or perennial garage sales. Every area has them.
Be ethical. If you can see the seller is in dire straits and needs money or if they are raising money for someone's surgery or a charity of some kind, don't be too aggressive in your haggling. You can get a great deal, while still being ethical.
One way to narrow down your search for treasures is to skip the time wasters, items that are not likely worth much, and zone in on the stuff that might be worth something. Some time wasters include books, newer toys, baby stuff, CD's, DVD's, posters, Beanie Babies, Furby's, magazines, electronics, computer stuff, etc.
Things to check out first, basically anything from the 70's or before may have some worth or potential future worth. Also, any antique or vintage clothing, jewelry, toys, household items, furniture, kitchen items, tools, glass, porcelain, pottery, textiles, clocks, silver and paintings. Head for anything that looks old or vintage and check it out.
Potentially great finds include:
- Signed art pieces or sculptures or unsigned art that is of exceptional quality
- Signed vintage and costume jewelry or unsigned jewelry that is of exceptional quality and good condition
- First edition and signed books by known authors
- Vintage toys of all kinds in good condition
- Vintage kitchen items including canisters, gadgets, hand towels etc.
- Vintage clothing in good condition
- Antique furniture in original condition with a natural patina
- Antique tools of all kinds
- Vintage or antique porcelain and pottery with marks
- Vintage or antique glass items by known makers
- Antique or vintage silver items
- Old embroidered textiles
- Antique clocks
Once you have your trunk full of potential treasures, it's time to go home and research your items. The Internet is a perfect resource for this. From finding websites or auctions selling similar items to getting book recommendations for offline researching, the Internet is a treasure trove in itself. Be sure to take advantage of it!