Icons, icons and icons!
Building any kind of web interface, particularly one that requires any kind of human interactivity, will at some time utilise icons. Whether they be on buttons, used in headings, or tabs or panels, icons are like little visual pieces of informative haiku: small, succint and should make you smile.
Lacking any drawing talent myself, I am always on the lookout for handy sets of icons. Sites like Smashing Magazine are often compiling fresh sets- and I can never get enough.
I find myself returning time and time again to one particular set, though, and that is Yusuke Kamiyamane’s Fugue set of over 2,600 icons. For just about everything you can think of. Kamiyamane has even included a search facility and has tagged each icon with a number of descriptive words to help you find just the icon you need.
If you’re building web interfaces I recommend you go get it now!