Do
not use global aliases. They are dangerous. It's too easy to accidentally use them without realizing it, with unpredictable consequences.
Much better is to use abbreviations which expand to the full command they abbreviate after you hit the space bar.[1]
This way you can see exactly what's going to be done before you hit ENTER. It does cost one extra keystroke, but the safety is worth it.
[1] - http://zshwiki.org/home/examples/zleiab
