The use of a lot of wide angle lens with the camera set close,low and even at odd Dutch tilt agles can add a sureal effect.A lot depends on how subtle you want to be.The Cabinet of Dr.Caligari used strange backdrops.Door frames are trapazoidal or parrallogram instead of rectangular.You didn't specify whther you are shooting video or film,but if film,the cross process of reversal film might be cool.Also shooting reversal film and processing normal will give you some bizarre results."Buffalo '66" was shot on reversal.Intentionally breaking rules like the axis can send a subtle message that something's not right,although you have to really careful with that one and be really subtle with it.Otherwise it will just look sloppy.Kubrick has done this a few times,The Shining comes to mind.Unmotivated light at odd angles,shadows that don't belong and odd colored gels may work for you.I'm reminded of some of the shots in "Event Horizon" where they used some really noxious looking green light in places.