The first thing that you can do is to word your ad so that it will attract more people. To do this you will want to keep things simple and to the point. Provide information about the manufacturer, the model, the tractors condition and the buying terms. Also remember to include your contact information.
To get the most from the tractors that you have for sale you may need to replace a few parts and clean it up. If the tractor or lawn tractor is beyond your repair skills then you can clean up the body and offer it for parts, or advertise it as a fixer upper. By cleaning up the body you will entice people who are looking for a project tractor. If your tractor runs, but not well, then you may want to replace a couple of the inexpensive parts to increase the tractors value.
When potential buyers arrive at your garage to view the mowers be ready to answer their questions and to show them what the tractor has to offer. If you don't have the owner's manual any more then you may want to download it from the manufacturer's site and have it ready for the buyer. Also let the potential buyer know what you have done to repair the tractor. Let them know that this tractor is a good investment and that it can be good as new with a little elbow grease.
If you aren't able to sell your tractors then you have another option to milk a little value from the old machine. This option is to donate the tractor to a local school's shop class. They can use the tractor or lawn tractor to learn small engine repair and you can right off the donation on your income taxes as a charitable contribution. This option not only provides you with cash value, but it also will help you to reduce clutter in your yard or garage.