Tip #1: Advertise! If you want lots of people, you have to tell lots of people! Post an ad on Craigslist or in the PennySaver (or whatever local ad publication your neighborhood has) and put up signs that are all the same color, so people can easily find you. Check your city website to see if you need to have a permit to have a sale.
Tip #3: Price Everything! I know you don't want to, and I know it's tedious, but people don't want to ask how much things are. If there are few things at the end that don't get priced, it's okay, since your other prices will give an idea of what to expect. We brought bins of stuff into the living room and priced in the evenings while binge watching episodes of Say Yes to the Dress. Even though you've set prices, always be willing to haggle with customers, or offer a deal if they're buying a lot!
Tip #5: "Nothing in your yard sale is ten cents." This is a direct quote from my aunt, as she was re-pricing all of our 10 cent items. She was right; if there's an item that you can't imagine selling for at least a quarter, throw it in the trash. By allowing junky items to sit among the nicer things, it brings everything down. So the only place your stained shirts, half missing boxes of crayons, chipped dishes, and gross flip flops should be going is the trash.
Tip #7: Keep your sense of humor. When you've been sitting outside in the sun all day selling your possessions for less than a dollar, it's easy to get grumpy, but keeping up a nice attitude and sense of humor makes it more likely that your customers will stay and shop around. My aunt has been known to write tags on beat-up old hats and toasters with statements like "Never worn!" or "High-tech!". Even if those items don't sell, you're likely to sell more stuff, just because you've provided a fun atmosphere. I went with a hipster section on the second day, which most people didn't get, but it was worth it to see the laughs from younger customers! (Please note the 2 buck Chuck boxes. I think I'm hilarious.)