What plays (ghost stories, tense dramas, etc.) have given you the shivers? What playwriting and staging techniques to you think are most effective to scare and thrill an audience? For all who reply, thanks for sharing your opinions.
Swann, could you give an idea of the ages of the young people involved? Some old fashioned scary folktales could be great for little kids--those stories with the "got-ya" endings turned into a short play (such as The Hairy Toe story, or my grandma's special "As I was spinning and I was weaving, I heard a noise . . .") I can send you more for little ones, if that's appropriate.
Also, Robert Frost wrote a wonderfule scary poem called "The Witch of Coos" (unreliable narrator and all), which could be dramatized for a slightly older audience. Some great images in that one--the skeleton shimmering like a chandelier.
I agree about QUILLS - but more so, that playwright (Doug Wright)'s other play WATBANALAND. Way creepier.
Also Sarah Kane's SAVED, PHAEDRA'S LOVE, and BLASTED, Caryl Churchill's VINEGAR TOM, any good more-guignol-than-camp production of Wilde's SALOME, the final scene of Cheryl L. West's HOLIDAY HEART, Lucy Gough's MAPPING THE SOUL, and (forgot the playwright's name's) THE OVERWHELMING.