Sometimes, it's the little details that make a viz go from good to great. Take the winning sports contest viz by Ben Jones, which tells a great story about sports droughts in North America in a clean, concise way.
This video goes into some key decisions--even small ones--that helped Ben's viz shine, as well as how to do them yourself. This includes little formatting changes (clarity), using the right level of detail on maps (accuracy), and a cool trick called data blending (to get the right presentation). Take a look:
You can see Ben's original viz on his site, DataRemixed. I highly encourage you to download it--click the download button in the lower right corner of the viz--and try rebuilding it yourself.