Zsh
One feature of any shell that is immensly useful is the history. Any command you made gets recorded, and you can then retrieve it later on with various commands (my favorite: Ctrl-R, which allows you to search through your history). At any given time, I usually have anywhere between 10
Zsh
REPORTTIME is a nifty feature of zsh. If you set it to a non-negative value, then every time, any command you run that takes longer than the value you set it to in seconds, zsh will print usage statistics afterwards as if you had run the command prefixed with time.
Zsh
If you're a command line junkie like me, your commands sometimes tend to get long and complicated. And then you spot a typo somewhere in the middle. Or you forgot a command somewhere. You now have two options: You can use the arrow keys (or, if you know your shell,