Now, you might not have the time or you do not feel comfortable with designing, so you can use a UI theme. There are a few floating around online, but here is the most popular one:
http://websymphony.net/almost-flat-ui/
If you want to use this theme, instead of downloading Foundation from the Zurb website, download it from the previous link. This theme is using the Sass version of Foundation, so you might need to follow the setup at http://foundation.zurb.com/docs/sass.html.
If you want to see what others have done with Foundation, you can always visit the Zurb responsive gallery at http://zurb.com/responsive.