Greetings commanders, seers, warlords, and servants of the hive. I hereby encourage you to post the background of your army, craftworld, or hivefleet, so that your enemies will truly understand that they should flee before your might, or be crushed by it.
Fluff should be posted for a lord, the lord's army, and their homeworld. You don't have to do all of them, these are just ideas to help get started.