I googled "Garage Sale Tips" and all sorts of sites came up.
Here are some pointers for throwing a great garage sale:
* The best time to have a garage sale is either Saturday or Sunday. The sale should start early (e.g. 8am) and run at least till noon. The majority of people who are serious about buying anything will be up and ready to go early. In fact, don’t be surprised to find people at your house before the posted time!
* Advertise your sale in the classifieds of your local newspaper. Mention the time, place, and date (include a rain date if you have one). If you will be selling anything unusual or items you think would especially attract people, mention them in the ad.
* Put up a bunch of signs in your neighbourhood a few days before your sale. Make sure the signs are large, legible, and, if possible, waterproof. On the day of the sale, put a large sign and a bunch of balloons at the intersection closest to your house. Remember to take down all signs when your sale is over.
* Ask friends, relatives, and neighbours if they’d like to join in or if they have anything they’d like you to sell for them. Not only does having more sellers mean less work, but offering more stuff will attract more customers.
* When gathering up items to sell, be sure to clean them up. Wipe dust and grime off of dishes and knick-knacks, wash and iron clothing and give furniture a coat of polish. Not only do clean items sell faster, but they will also sell for a higher price.
* Put prices on each item in advance (don’t wait to do it the morning of the sale as many buyers come early and you want to be prepared for them). Either write prices on labels for each individual item, or use a colour-code system (e.g. all items marked with a red dot are $1). If you decide to do the later method, be sure to have several clear signs that state each colour and the corresponding price.
* Remember that people who go to garage sales are looking for deals. So don't overprice your items. Plus be prepared for people trying to haggle the price (you can either give it to them at their offered price, haggle back or tell them that the price is firm). As it gets later in the day, you should be more and more willing to lower your price.
* Make sure you have enough tables to neatly display all your items (if necessary, make temporary tables out of sawhorses and pieces of plywood). This will allow your customers to check out everything easily without the pain of having to dig through boxes.
* Set up a small table for your cash box, a printing calculator and some used plastic shopping bags that customers can have to put their smaller purchases in. It’s also a good idea to put any expensive items like jewelry on this table so you can keep an eye on them.
* Make sure to have ample change and small bills in your cash box at the start of your sale (you don’t want to have to turn away customers because you can’t break a $20 bill). Mark down the amount of money you begin with so you can figure out your profit at the end of the day.
* Always have at least one person helping you. This person can make sure customers don't steal anything as well as watch the cash box if you’re off helping a customer.
* Taking the time to organize your items into categories will make your sale more visually appealing and will result in higher sales. For instance, put all of the books together, group all the glassware in a section, and line all the shoes up along the edge of the driveway.
* Put any large or attractive items (e.g. couches, TVs, playpens) in plain view of the street as this will help to attract people driving by.
* Display clothing neatly on a rack or hang them on a broom handle suspended between two ladders. Use a professional tagger (available in most craft stores) to label each item with the size and price. Put the tags in the same spot (e.g. hem of the right sleeve) so people can easily see them without pulling everything off of the racks.
* Instead of selling all kinds of small items for 10 or 25 cents each, package any similar items together and give the package a single price (e.g. bag of assorted hair accessories for $2).
* Have an outlet available so customers can test out any electrical items to ensure they work. Have batteries on hand for the battery-operated items.
* A great way to make extra money is to also sell bottled water, pop and/or snack items like donuts. Many shoppers will be in the mood for refreshments (especially if it’s a hot day) and hungry from all their treasure hunting. Put items in a cooler by the cash table with a visible sign letting customers know what’s available.
* It’s common for there to be lulls in between groups of customers. During these quiet periods, take the opportunity to tidy up. Spread out remaining items to give the appearance you still have many things left.
* Always remember the number #1