The cheapest and easiest way is to add a quality original informative site to it and then wait. It will take a while, but back links will be made, people will start discussions about it and slowly but surely your name gains recognition and the sites reputation rises. Social links are made and Page rank rises.
Write articles and include references to the site, get in forums and answer questions that are covered in your site. Do this with forums that allow you to have a link in your signature etc, etc.
If you want a reputable domain quickly you can buy one on the open market but it will cost you a lot of dollars for a really good one!