Here are some tips for maximizing your potential in selling your goods online.
1 - Put where the item is located in your title. (Ex. SA, Austin, Houston, etc.)
2 - Take clear pictures of the item showing all flaws and facets.
3 - Be upfront about the condition of the item.
4 - Post a price; no one wants to deal with an auctioneer.
5 - Deliver the item within a respectable time frame; if you have an issue be sure to address it.
6 - Properly package the item.
If you do this then you leave little to chance, and soon will develop a positive repertoire amongst the buyers on the forum.