I am pretty sure most people who uses Linux knows these, but they are quite handy and it is not the kind of thing I usually see online, so here it goes a small list of shortcuts to be used on your favorite terminal/shell.
Let's say you were copying a file from a virtual domain to another one, so you type:
$ cp /var/www/old-website.com/public_html/mail/index.php /var/www/new-website.com/public_html/mail/index.php
So you remember that, actually, you want to move the file, not just copy that. On that case, you want to repeat all the parameters but the main command. So you can achieve that with....