Christmas comes but once a year, thank Christ (literally), and the place is probably full of candles. If you're really lucky, it will be full of pretty girls (or boys, if you prefer) too... Anyone looks good in candlelight, even me.
Shoot on a tripod, work the exposure via a histogram (because your screen will be bright, so don't just guess), bracket, focus with the room lights on (because otherwise your AF will relentlessly pick up on the candles), have fun.
Maybe you'll get a Christmas kiss.
This one was done with an Olympus E500 (terrible low light camera, but we managed, just) and a 50mm f2, which is the equivalent of a 100mm on a Full Frame camera. Always use a longish lens when photographing glamour, or the poor girl will end up looking like Schnozzle Durante.