The first priority of your listing design is to showcase your goods for sale in the most flattering light possible and within the context of your broader business image. The last thing you want to do is distract the viewer´s attention from the item he is considering purchasing.
eBay´s Turbo Lister, Listing Designer and other third-party listing services such as Vendio, InkFrog and Mpire all offer WYSIWYG (What You See Is What You Get) HTML editors. The primary mistake that many sellers make when they get their hands on a WYSIWYG editor is that they go way overboard with bells and whistles.
They use busy backgrounds and too many different fonts, colors, and type sizes (or even worse, animations, music, and scrolling banners). By the time the listing is created, it looks like a kaleidoscope. The listing viewer becomes confused and distracted, not to mention turned off by an unprofessional-looking site.
Tip: Reduce the amount of bells and whistles on your eBay listings and Store designs. Since over half of the country is still using dial-up, putting extraneous items in your listings creates slower downloads and may drive your customers to your competitors.
Thoughtful design decisions, mitigated with a bit of restraint, tones down all the visual "noise." The point is for your design to complement, rather than compete with, the item that you wish to sell.