For the office holiday party: Tuck your glitzy top into black or grey trousers and add a black cardigan. If you want to add a pop of color, opt for a red pump. Even for work parties held off premises, make sure to have a cardigan handy; if these are people you mostly see in a work environment, then even your social outfits should feel professional and polished.
For a night out with friends: Slip into your most flattering dark wash jeans and leave your glitzy top untucked. If you think you will be cold, add a black blazer with the cuffs rolled up, however If you're going somewhere warm, like to a crowded bar, skip the outer layer. Add a sparkly bangle bracelet and your favorite heels.
For your friend's holiday open house: Tuck your glitzy top into a neutral colored pencil skirt and add a bright cardigan (I'm partial to burgundy and emerald). You will probably be standing around so finish your ensemble with a comfortable pair of flats or wedges. Unless it is an evening affair, feel free to skip the sparkly jewelry since your top is already the statement piece.