Hrm.
Physical: Cold iron, fire, wood, leather, that sort of thing for substance-catches; strangling, bludgeoning, cutting, or stabbing injuries; "things that have been alive"; a single weak point that's easy to hit, as long as you know it's there.
Mental: Mental stuff's often used for resisting torture, so maybe strobe lighting (or even just bright lights) are the sort of thing that come to mind; more esoteric things might include a prolonged loud or dissonant noise, or any simple technique anyone could set up- dripping water, sensory deprivation, hair-pulling...
Does that help?