From the post:
Over the last few years I’ve created a few popular visualizations, a lot of duds, and I’ve learned a few lessons along the way. For my latest analysis of where Facebook users go on vacation, I decided to document the steps I follow to build my visualizations . It’s a very rough guide, these are just stages I’ve learned to follow by trial and error, but following these guidelines is a good way to start if you’re looking to create your first visualization.
If you want to get better at creating visualizations, this is a post to read and re-read, on a fairly regular basis.