my recipe for decent halloween party pics:

- dress ostentatious and in this particular case you won't attract any attention,

- don't pre-announce your presence, which makes all the guys act naturally and (almost) artless,

- take your widest option, use the lens wide open at largest aperture,

- always bounce the flash to the ceiling, work in shutter priority or manual mode (despite the short focal length you should try to keep the shutter speed faster than 1/60th of a second for indoor party pics),

- select mid-balanced exposure metering mode, exposure compensation -0.3 to -0.7ev,

- deactivate the autofocus and set the focal distance to minimum,

- tilt the screen for a pov from far above; always use this angle for a special, scary look,

- focus and shoot the most interesting guys just by varying the distance to the subject,

- show the subjects the (first) results on the camera screen,

- whet the appetite for the final results by shortly (!!!) describing the possibilities of an appropriate pp,

- don't forget to share the contact information... for your amusement in 2014!

btw: absolutely great costumes, folks! we had a lot of fun last night! cu all in 2014!