The Holidays can be tough for some people, so don't make it tougher on yourself by wearing the wrong outfit and feeling out of place.
Company parties can be the most awkward and a lot of the time they will make it easier on you by offering a dress theme. If you follow the dress theme you will be safe, but if you feel like veering off on your own path, a suit or sport coat with slacks can help save you any embarrassment.
A tux is a nice way to say you take pride in your appearance as well. Jeans and a t-shirt is definitely not the way to go. Wearing tactful Christmas colors like red and green can be fun too.
Holiday get togethers with friends & family is usually a much more casual occasion. A nice pair of jeans with a fun Christmas sweater or a pair of slacks and a collared shirt is most appropriate. A nice sport coat to go with your outfit is always a nice touch to any outfit.
Have fun this holiday season and leave any worries for 2017!