i got some boots, skinny jeans, gloves, scarf, hat...
Get a pair of tights to wear under the jeans.
Hats stand out - unless worn by elderly ladies. It's not what girls usually wear, and, btw, a hat is not good for frosty weather - getter get something that would cover your ears.
Gloves and a scarf are a must.
Make sure your boots don't soak easily - temperatures around 0 are very common in December, so there's a lot of mud and half-melted snow in pavements. It's a good idea to wear skinny jeans with boots because boots are easier to clean that jeans :-)