There are basically to schools of thought on garage sales. One is to make some quick cash, prices are higher, items are better quality, things you normally wouldn't get rid of. Two, is to get rid of stuff you never want to see again, prices are low to move more items.
So, which way do you want to go?
I personally have had both kinds. I sold cute clothes that I had really wanted to keep for yonger grandkids, baby beds and toddler beds I really didn't want to get rid of but they sold and I paid the bill I needed to pay. I had the baby bed for $30.00 w/mattress (it wasn't great, had some wear and starting to get holes on the corners) or they could buy the toddler bed with the same mattress for $25.00, which ever one wanted the mattress got it. They could buy the items without the mattress cheaper. The person who bought them bought them both for $40.00. I felt lucky to get that much.
A sack sale is good if all clothes are kind of equal. You can't sell some clothes in the sack sale but others are priced individually. If you are willing to let everything you have go for a dollar a sack or two dollars a sack, like a walmart sack, then go that way, you'll sell more clothes and get rid of them.
What I have seen in the past few years is that when I go to a garage sale where younger people are selling is that things are way overpriced. One even said "I paid $20.00 for that top and I want $15.00 for it". She wasn't selling anything.
So, my advice is, if you really just want to get rid of things, is to price clothes a dollar or less. As for the furniture, you might do better online at the places mentioned in other posts.