Enliven your site with contrast and color between graphics and text. Focus on your purpose. Cool graphics or large dense blocks of text may interfere with the communication of your message. Every single item on your page should have a strong reason for being there. Test your links and tags and check your spelling.
Nothing ruins a good impression faster than a lack of attention to detail.
A successful site is the result of design choices that are targeted to your site's purpose and audience. Choose design elements that help your users understand your message. A site of serious subject matter, such as one for a cancer support group, requires different design choices than a site for a school. When choosing a layout or specific graphic elements, such as logos or photographs, pick those that supplement your message instead of those that merely decorate the page. The location and size of type and graphics provide visual clues to the user about your message.