Pick up some weights
In the days leading up to your devilish fete, you should aim for 45 minutes of cardio, along with 15 minutes of weight training. We should all know by now that muscle makes you leaner, not to mention more toned. Right before slipping into your costume, do some push-ups and crunches to increase blood-flow and amp up muscle definition.
[Photo via @kayla_itsines]