Movement
Lunging and chases have their place, but they can be overused. Sudden movement and obvious aggressive actions produce more of a startle effect or a defensive reaction. While these can be amusing, they are not as effective as true fear and dread. Keeping the concept of "otherness" in mind, make your movements different from what your victims might expect. Our deep-seated fear of things unknown and alien is a rich area from which to produce chills.
The extremes are the most productive. Either move so fast (or appear to) that they almost can't see you, or move so slowly and deliberately that they can't take their eyes off you. Isolate your gestures instead of moving your whole body. A small movement of your head, in an otherwise still pose, can be much more dramatic than a lunge. A slow curling of the fingers in a "come hither" gesture can be much more effective than a grab. Moving just your eyes in answer to a question can communicate more than words. Simple, deliberate motions, well timed, can push those fear and dread buttons in your victims' heads.
Check out the example description from the Haunted Theater.