- Telling players to make a perception check and then telling them "never mind you don't notice anything unusual"(a sort of Meta-Game version of "Signs of Activity")
- Take a player out of the room for a chat. Then drop clues to make the other players suspect that his character has been replaced by a doppelganger
- Have the party find clones of themselves, so that they begin to ask "am I really me"
- Having Rats, taxidermy- whisper in a PCs ear "Run away while you still can"
- Creepy Music to fill "DM preparing something" breaks, so people don't start joking and kill the atmosphere
- Have players create a characters descriptively, don't even tell them what game/system they're playing
- A PC starts growing webs between his fingers/developing mutations
- Creep out players: An NPC says "the buttons on your shirt look like my doll's eyes"
Some of these ideas I really liked, others less so. Anyway, among all these tips for creating mood was this one:
Don't use miniatures!
Now that one took me for a loop. I'm not the biggest user of miniatures, but I do occasionally put them to use to set-up a particularly large or complex battle. Why are miniatures so supposedly antithetical to a Horror game?
The answer that the panelists gave is what they call the "Found Footage Element". You want the players to see, in their mind's eye, what the character sees. As soon as they are using miniatures instead of their own imaginations, then the storyteller's magic is dispelled, together with any potential for fear.
Anyway, that's the idea. So when I'm trying to set-up a complex encounter which will challenge the players to come-up with original tactics to overcome their adversaries, then I'll bust out the miniatures. But when I'm exposing them to the brooding horror that dwells beneath the Earth, then I'll leave the props in their box.