Lots of kids' clothes, neatly organized by size.
Adult clothes, stacked neatly on a table, and hung on clothing racks so everything could be looked at easily. As clothing on the rack sold, we moved more of the clothes off the table and onto hangers. (If you regularly hold garage sales, I highly recommend investing in a clothing rack. People like looking at hanging clothes, and they seems to sell faster than those stacked on the tables.)
Jewelry is hung on a framed piece of pegboard so that it is easy to see and stays untangled.
Everything is grouped with similar items. As items sold we unstacked items and spread things out a little more.
As the day went on we just kept spreading things out as more room was created by sales. After each rush of customers we re-folded and re-stacked the clothes, as needed, to keep everything looking nice and neat. When it was all said and done I was very happy with the amount of stuff I was able to get rid of. Here is the after view of my garage sale storage area of my basement. (Here is the before of the space.)
Do you have any tips for holding a successful garage sale?