Story of my life:

Step 1.) Find a minecraft server.
Step 2.) Join that server
Step 3.) make sure that you can /me on that server
Step 4.) stash all your stuff
Step 5.) Leave spawn and go to wilderness
Step 6.) Wait for someone to die. remember exactly what is written when they die (i.e. Steve was slain by Skeleton)
Step 7.) Go into mine
Step 8.) find a deep, dark part, hide in there
Step 9.) Do /list. You want to know who your audience is :). (make sure there is at least 5 people. this is only funny once)
Step 10.) Type holy $#!+, its Herobrine, holy $#!+. (or something along these lines)
Step 11.) do /me was slain by Herobrine (or if it is a custom message change it)
Step 12.) /spawn
Step 13.) Laugh

Hope this helps. Please diamond, favorite, and subscribe