Kitchen stuff, like glasses, a couple plates, one wine glass.... sells. Have a 25 cent table for the children attending. I always have a bin marked, 'Free with $5.00 purchase." People will look and look until they come up with $5.00 so they can get the free item they want.
Hang up your clothes. You will make more money for them. I sold my children's clothes, in almost perfect condition for 1/4 of what they cost. Adult clothes you have to sell for VERY cheap, like $1.00 or less. (Children's clothes with stains or holes will not sell.)
Price your items just a bit higher than what you want them to sell for. People like to think they got you to come down in price. Don't price too cheap, like 10 cents, because people won't buy it then. No idea why this is.
Pricey items, even if they are a fantastic deal are very hard to sell. For instance, let's say you had a great set of luggage, perfect condition, and you asked $50.00 it might just sit there, BUT if you had a cruddy set of luggage for $5.00 it will sell. So dig out EVERYTHING from your home.
Get some cheap clear baggies, and bag up items that might otherwise get misplaced from a set.
Wash everything.
Use two ladders and a broom to make a hanging rack.
Many people like to talk. Say hello. Strike up a conversation. You'll be able to tell who likes to chat.
Whatever people can see they will say, "Are you selling.....(fill in the blank), so cover it up with a blanket if you don't want to deal with this conversation or do as I do and say, "SURE!" and give a very high price.
Make people's day. I had one family buy a little Tykes car, and I walked over an gave them the gas pump for free. They were shocked. It was fun.
Set out like items together: all the holiday decorations in one spot, all children's clothes somewhere else, household on another table....
Do not make people dig through a box of random items.
Tables yes you need them. Some folks cannot physically bend over to reach the ground, and they won't be able to touch the item (key to selling).
Have some chalk for the kids to draw on your driveway or sidewalk while parents shop.
Have bags available. Cheap plastic is fine. People will want these.
Be calm when you count up purchases. Buyers will try to hurry you and say,"Oh here's $20.00 for the whole thing," and you know it's $40.00 of merchandise. Some folks are simply in a rush to get to the next yard sale, and others are trying to get a great deal. Just smile and count slowly.
Same with change. They'll say, often with impatience, "It's 2.50." Take the time to figure it out.
If someone hesitates on a big ticket item ask if you can have their phone number and if you can call them at the end of the day if the item is still there.
Do you have anything you simply want to get rid of? We had some extra bricks from a patio project. (We got the bricks for free.) We marked them free, and sure enough someone hauled them away.
Thursdays and Fridays are the big garage sale days here. Saturdays people do not arrive until after 10:00. Sundays you will have a rare customer.
These things are a ton of work. Decide if you ever want to do it again. If you do box up all the leftovers. Store them out of sight (so you don't go through them) and set them out again next year. If not, have someone come on Monday and donate all the leftovers. Or put out large items, and someone will drive by and pick it up for free.