Be from somewhere where murder isn't an everyday occurrence and people actually care when you go on a shooting rampage. If you speak English and are white, you probably have this covered.
Play video games and listen to metal. They will train you to kill better.
Leave behind lulzy statements and media so that you will be remembered. Nobody cares about a vanilla killer.
Kill people who have absolutely nothing to do with your problem. They still deserve it.
Offing yourself does not count as a kill, but it does make you an hero.