I was reading the manpages for bash on the plane and I stumbled across the HISTIGNORE variable. To test it out, I immediately edited my .profile to define this variable:

export HISTIGNORE=ls

I tested it out and this is great! It excludes plain 'ls' commands from my history without excluding more interesting commands with lengthy paths, but having recently harvested a great deal of wisdom from SU I am eager to know what other commands superusers might recommend or other lessons learned.

What can you share about using the HISTIGNORE variable in bash?

(Note: I'm about to board my next flight and I have obligations upon arrival, so I will be absent for a number of hours before I can respond to comments...)