The organizational method above is a way to "prepare to improvise." What is actually put in play is "out of your head," as you say because you have to add context to the broad ideas in the bullet points. @Voth: The "faction" is actually called a "Danger," since a "Danger" needn't actually be a group of people or creatures (e.g. it could be a place). A Danger pursues an ultimate goal called the "Impending Doom." When a Danger achieves its Impending Doom, the Danger is resolved and the very bad things the bad guys were trying to do are now part of the world. So, "Grim Portents" are potential events leading up to the Impending Doom. They codify the plans and machinations of the Danger in a vacuum. Without the PCs or other events intervening, the Grim Portents come to pass, one after another, until the Impending Doom comes into effect. They are the sword of inevitability that hang over the PCs. Generally speaking, they are a chain of events, but sometimes it can be just one event or a number of events that needn't be "in order." The reason you use multiple Dangers (I like no more than 3 per adventure location) is to create dynamic play. One Danger, such as a tribe of goblins in a dungeon, represents more linear play.
