I've done numerous Garage sale's and I cant stress enough
MAKE GOOD, READABLE SIGNS
The one's I've had the best luck with is Heavy NEON posterboard. I usually do the bright green with BLACK letters.
They show up really well.. do them all the same color, post at least 20 signs.. I usually make about 40 and at 4 way stops
I put 4 of them facing each way. Put them at main intersections up to a couple miles from your house. Then make sure you have
more signs along the way leading them in. I've also added arrows to the signs as people dont have a lot of time to read signs when driving, just
point them in the right direction, and they will get there. I put the bare minimum on signs , usually just " HUGE yard sale ( its shorter
to write than "garage" , then " Fri/Sat Only" and an arrow pointing them the right way. . I may put more on a bigger sign at my actual street, like the address.
I use a staple gun. Dont make the signs so big that they bend in the wind and are unreadable. Usually just a square 12"x12" sign is fine.. remember simple
large letters that are readable from a car a couple car lengths away. If it's too busy of a sign.. people won't waste their time.
Also nothing worse than following signs and having them stop suddenly and you dont know where to go.
What I do sometimes is cut out arrows in the neon green, then you can attach them separately or even just use an arrow where there
are long stretches of road.
I also always do Fri and Sat only now as Sunday is usually a waste of time. Fri is the best day. You get the serious garage salers on Friday. Also more
people stop because they figure it's your first day. Sat is always good too as many figure that is your first day but still never as good as Friday's here. Sun people figure it is really picked over and they skip itor they come after church and are looky loos...
Use a fanny pack with your change in it or have one table set up that is manned all the time by one person and then other workers walk around and keep their eyes on stuff and answer questions. Also MARK Everything. People hate asking "how much" I also always have a box with small "free" trinkets to draw people in and keep kids busy looking through while their parents shop. If you have multiple people at the sale with items, we usually have people put their initial on the price stickers .. just to keep the confusion down, then either each person does their own money transaction or we have a tablet and write down the dollar amount under the person's name and keep one money box and pay out at the end.
Also do not let people in your house to use the bathroom .... my friend had her jewelry stolen out of her bathroom when she did that. It's just not necessary or worth it to let strangers in your house ( you probably wouldnt but just in case)
I think others mentioned getting plenty of change.... the first few people seem to bring ATM $20's so your change can be cleaned out quickly if you only have a little. I usually have about $80, $30 in ones, a few $10's, the rest $5's and about $5 in quarters . We usually price everything to be at least a quarter so we dont have to deal with nickels and dimes.. those items go in the free trinket box
Hope that helps! I've had some huge sales... made $900 once and I only had two large items... one $100 and the other $80 , everything else was under $20. It is amazing how well you can do if you have good signs drawing people in.... and also amazing the crap people will buy! LOL
Good luck!