Two foreboding techniques I tested in (pen & paper) role-playing storytelling that were supposed to raise suspense and broaden the picture, but failed miserably.
Mike, a good friend of mine, and I both experimented with “foreboding” in our respective (pen & paper) role-playing groups. His turf was the grim post-nuclear setting of Twilight 2000, mine the universe of the Alien franchise. Both groups had developed over years and years with regular players (and regular sessions); the rules, from a certain point in time on, were in both cases self-designed with several major revisions over the years; and the respective stories and plot lines, in Mike’s case rather often, in my case almost always, were written by ourselves, respectively.
Mike experimented with “Foreboding” as a skill; he threw the dice surreptitiously from time to time for those characters who were in possession of that skill, and if something came out of it, a character would have a “strange dream” or vision, the accuracy of which would depend on the outcome of another hidden dice roll.
With my group, I tried something completely different. From time to time, I cast myself into the role of “omniscient narrator” and related far-away events and dialogs that obviously had a bearing on current events, but were too vague or too remote or both to actually help my characters make decisions, or act upon it, or do anything “unrealistic” along these lines. Besides providing a somewhat “bigger picture,” it was, as Mike’s technique, supposed to raise suspense.
I can confidently say that both variations failed miserably. They tended to be more confusing than atmospheric, and important points would be forgotten, long before any “Eureka!” had a chance to get its due. Bummer.
What I remember is this: it’s quite some fun to sketch these things, but it’s more fun for you than it is for your readers (or the player characters, in this case). It’s always better to keep things in perspective. If you don’t want to develop such foreboding events into self-sustaining side plots, or can’t, then drop it. It’s artificial, it’s contrived, and it’s the easy way out. You need to learn to keep everybody interested even during times when you’re not throwing bullets at your (player) characters!
This is not the last word on the topic of “foreboding,” of course. There’s more techniques around, and more subtle ones at that, and more useful ones too.