finding and visualizing disk usage

I was working with someone to clean up their hard disk because it was getting full, and it was not very apparent where the space was going, so I introduced them to WinDirStat, and it showed the sore spots for usage.

If you are on Linux, the equivalent that came first is KDirStat.

I like it when cleaning up, but usually I end up using

du | sort -n

and working my way from the bottom of the list.