My kids discovered a few years ago that cans of pop went better than lemonade. It's less work for you and people will pay fifty cents for a can, easy. They made a killing! I had to go get more pop after about an hour and a half.
Our last sale we went with a color coded pricing system for most of the items. All blue dots were 50 cents, yellow dots were $1, etc. We put up a BIG sign that had the key, so people would know what the dots meant. You can also put initials on the dots to keep track of who the item belongs to. It just saves time pricing items if you don't have to write the price over and over.
Good luck. Hope you make a bunch selling what you don't use!