I have not read the listed link but I have had many successful sales. A few tips:
1) Hang up as much as you can. People don't like to look through piles of clothes and piles are constantly messed up. Hanging them with size indicators makes it easier for both you and your customer. I lucked into getting a circle rack when a local store went out of business. I also have a shower rod that is hung from the garage rafters for more hanging room.
2) Make sure the clothes look nice. I always thow a load into the dryer with a wet washcloth to get the wrinkles out which is all it takes.
3) Have a neat and clean sale. I always have compliments on how nice everything looks and if the garage is clean then they are more likely to stop. I also buy inexpensive white plastic table covering that comes on a roll just to make all the tables look clean. One roll lasts me quite a few sales.
4)The more you can spread things out the better. Again you don't want people to have to dig to see things. I put many tables around the perimiter of the inside of my garage and then put two tables down the middle. It allows everyone plenty of room to walk around and be comfortable.
5)Put things on the driveway. It is the first thing that attracts people driving by. I always put at least one table outside. Then all the bigger things are also put out.
6)Advertise, advertise, advertise. Certainly placing an ad should be done but also be sure to put out nice big signs (if allowed in your community) to make sure that everyone knows how to find you. There is nothing worse then to invest all the time putting it together only to skimp on the signs and not get the business you hoped for. One tip-if you live in an area that prohibits signs you can get creative. Find a major street near your home that you are allowed to park on. Put a huge message on the windows of your car either with signs or something washable stating where your sale is.
It is so satisfying after the sale counting up the money you make and it also gives you more room. I am having my 5th sale Friday as a matter of fact and the garage is almost ready. There is always some last minute details though. Good luck