To give your auctions a consistent look and feel, you create a template (or pattern) that each auction follows.
When deciding whether to create your own template or find a prebuilt one, consider how much control you want to have over the design. If you're comfortable using a template that other sellers are using and can live with designs that don't allow much customization, then a prebuilt template may be for you. However, if you want to create a truly unique design and don't want to have any limitations placed on your creativity, it's time to dig into HTML and create your own!
A quick search on Google for eBay auction templates yields over 100,000 results! Within the first few pages of the results, you'll find numerous sites that offer hundreds of custom templates. Although some sites offer free templates, most require you to sign up for their services. They typically charge a monthly fee in return for access to their template libraries and other services.