Here's an oldie but a goodie. Confounded by trying to track down fancy-looking WordPress themes? Check out this Web-based theme editor that lets you tweak every nook and cranny of a theme then spit it back to your server to go live. You can add columns, change fonts and backgrounds, even throw in a customizable tag cloud--all with no coding experience required. All you need is a little creativity and some working knowledge of drop-down menus.
While some WordPress themes have excellent built-in support for doing this right from the WordPress dashboard, many more don't, and trying to figure out all the little things like text color is made far easier with a WYSIWYG editor than with WordPress' built-in editing tools.
Advanced users can throw in graphics or design elements they've hosted elsewhere on their server (as long as it's got a URL to link up to), and when all is said and done each bit of the theme can be grabbed as an individual file to whatever theme you're currently using. This is an easy way to try out new fonts and colors without making a mess out of your existing style.css file.