If you've never had a yard sale before it can be intimidating. I've bought and sold at yard sales my entire life. When I'm having a yard sale there are a few things I make sure happen in order to have a successful sale.
1- Get the whole family on board. I do this by using our yard sale money for a family goal... It's been a day at an amusement park, a camping trip or something we've been wanting to buy, like a new TV. I make sure it's something everyone is excited about and announce the goal early. When the family knows what the money is going for, they're a lot more likely to help out. About a month before the yard sale date I have everyone start clearing the clutter in their rooms. I give each person plastic store bags and have them try on clothes to see what doesn't fit, sort through their books and toys and really just hunt for things they don't need or want any more. They start bringing me bags of unwanted goods and their rooms get cleaner!
Assign the kids times they will be helping at the yard sale, either cashiering or just being a runner for you. I don't make all my kids stay outside the whole time at our sales, but I do make them each help set up, take down and work a two hour shift.
2- Price your items. I hate shopping at yard sales where nothing is priced. You can price everything individually with price tags, (the dollar stores carry tags.) or you can have tables organized into .25, $1, etc. Whatever you decide, just make sure things are priced! Even worse than not having things priced are the yard sales where nothing is priced and when you ask how much something is they say, "I don't know" or "I haven't decided" or "I'm not sure what it's worth". If you can't put a price on something it shouldn't be at your yard sale! You can buy tags that already have the .25, .50, $1 & $5 printed on them, or you can buy blank ones where you write your own price. I kinda like the blank ones because I always run out of the amounts I use a lot of on the preprinted tags. Be sure to price your items at yard sale prices. If you don't know what yard sale prices are like take a couple Saturdays and go to other yard sales before hosting your own. You can always tell the yard sales where the people don't shop at sales themselves because of the high prices. Just because you paid $50 for a shirt, doesn't mean someone will pay $20 for it at a yard sale.
Average prices vary based on where you live, but in my experience typical yard sale pricing ideas are-
shirts, shorts, skirts: .25-$1
jeans, dresses, jackets: $1-$3
baby clothes: .25-$1
shoes & boots: $1-$3
dishes & random household items: .10-$1
baby swings, strollers, bouncers, high chairs: $3-$10
larger picture frames & mirrors: $1-$5
small appliances: $1-$5
large appliances: $10-$50
Some of the best yard sales I've been to have had one set price, like .25/ea for everything or fill a bag for $1. If you have A LOT of stuff to get rid of this may be the way to go!
3- Advertising. About a week before your yard sale create a facebook event for it so your friends and family know it's happening. If you feel like you'd like more variety at your sale, ask for donations of items that people you know would just be getting rid of. If you have a friend who's been wanting to do a yard sale, you can team up together. The more items you have the more likely people are to stop and browse. If you choose to do a yard sale with another person make sure you have a good system for tracking whose items are whose.
A day before your yard sale advertise your sale on a free online classifieds site, like craigslist or ksl classifieds. Be very detailed in your dates, starting times and address. You have no idea how many yard sale listings I see that have been written up in detail with all the amazing things they have for sale and no address. Without an address no one will find you!
Saturdays are the typical yard sale day around here. I know some places do yard sales on Sundays. Make sure you know what the norm is so you can plan your sale on a day when more people will be out yard sale hunting. A few years ago I started hosting my yard sales on Friday nights from 5pm-dark and again on Saturday mornings from 7am-1pm. My Friday nights bring in as much money as my Saturday mornings! People are always looking for things to do on Friday nights. I set up in the afternoon and I'm busy all night. Once it gets dark I turn off my porch light and I've never had anyone bother anything set up even though I live on a busy street. Then at 7am my sale is already set up and I just hop out of bed and start selling!
4- Signage. I feel like this needs its own category because it is so important! One of my biggest yard sale pet peeves is signs you can't read. People will put up a sign with LOTS of wording on it. I'm sure it says the address, times and everything they're selling, but no one can read it! People driving around are driving. They can not stop and read a sign. All your sign needs to say is "yard sale" and have an arrow or a large plain address! If it's a bright color that's even better. Put an arrow sign at both ends of your street. Yard sale hunters have an eye for them! I can spot a yard sale sign a mile away. If I spot a sign and then passing it all I see is a bunch of dots on a page because there's too much info written on it I probably won't be stopping at your sale. Be polite and take down your signs at the end of the sale. Don't let them turn into litter.
Some cities do not allow yard sale signs to be put up, so be aware of that. To get around that people will park their cars with yard sale signs on them at the ends of streets. This has become very common and it works as long as you listen to my rant above. See the itty bitty yard sale sign in the picture. It was perfect! A bright green sign and an arrow! I've found yard sales in crazing winding neighborhoods just by following arrows...nothing else, no words, just arrows. I'm guessing those people shop at yard sales themselves!
5- Setting up. If you have tables, that is best, but blankets on the ground work too. I usually have folding tables for everything except the clothes. I put the clothes on blankets on the grass. I typically have tons of clothes so I just sort them into a blanket for kids' clothes, a blanket for ladies clothes and a blanket for men's clothes and price all my clothes at .50/ea. It's simple and it works. Make sure you're set up at the time you say you'll be set up. Be prepared for early birds. I don't mind them! They're usually good shoppers. I just tell them I'm still setting up so more stuff will be coming out. Have a place to take cash. You can either have a cash box or just wear an apron. Make sure you have lots of small change including a roll of quarters and lots of ones! People shopping first thing in the morning usually have $20s because they just came from the ATM so make sure you've got all the change you need.
6- Customer interaction. Greet every person who comes to your sale. Say thank you to each person as they leave whether they bought something or not. Be willing to barter. If people totally low-ball you and you can't take an offer that low try to counter offer with something closer to what you need to get out of it. If people ask if you'll do a bundle offer try to accommodate them. It encourages them to buy more because you're willing to give them a good deal. Count back change out loud so there is no confusion with money.
7- Cleaning up. At the end of your sale you'll have to decide what to do with the leftovers. I typically clean up all my tables and blankets, move all the items from the sale closer to the street and put a free sign on everything that's left. It usually cuts my leftovers in half. Some people like to save their leftovers for another yard sale later in the summer, but most people donate them to a thrift store or to someone else having a yard sale. I've picked up yard sale leftovers from others in preparation for my own yard sales. You can advertise your free items online. By dark I have them all gone whether they're picked up or donated and I'm so glad to be done!!!
If you have any yard sale-ing questions, feel free to ask!