That's quite an open ended question...
Use Google's web fonts service. http://www.google.com/webfonts/
We no longer have to be constrained by considerations of what fonts are installed on the viewer's computer...
Experiment with CSS. Probably the single most important skill for making your website look good. CSS Tricks (http://css-tricks.com/) has a great selection of tutorials, which are now graded by difficulty level.
Add more content; set some time aside for writing articles, etc. - give people something to read while they're on your site.
Use textures for your backgrounds; there's plenty of free images that you can find on the web, which tend to make things look more interesting.
My current websites are at http://www.daihuws.me.uk/ (WordPress blog - mostly incredibly geeky articles) and http://www.crisialu.co.uk/ (business - incorporates a blog, but for a more general audience). Now, I dare say there's room for improvement with both of them, but they both use relatively simple techniques to make them more appealing..