The very best way is to have a full page on a website and then post on Craigslist or some other place with links to every single detail and picture you can put together.
I sold mine with an ad on CL that linked to a hidden page on my business website. Here is the link if you want to see what it looked like. Sold in 15 minutes when I put it up on CL.
http://www.coloradoadventuresports.com/Malibuboatforsale.htm Also, advertise in warmer areas such as Texas and Florida.