Bash Commands to Try

Something I think anyone who spends more than a few minutes in the terminal could benefit from -- pushd/popd

If you find yourself changing directories a lot, give it a look.

Shell expansion is huge too, like you often don't truly need to spawn a sub-shell into `seq`

Edit: Some more thoughts, instead of just giving commands - try to elaborate on their options a bit.

For example, with 'sort' -- most people will want to know about '-r', '-h', and '-n' for sorting, and '-k' for columns