Here at the Geeky Gentleman, rather than dragging out those old, bulky coats, we’re preparing with a different approach: layering. The idea is simple enough: Wear a few different items (from shirts to sweaters and jackets) to keep out the cold. But with a few basic principles, layering can be a very stylish answer to a practical problem.
1. Layers allow for a level of complexity and detail, but just like the baroque style in art 
(known for its often flamboyant and intricate level of detail), there has to be some order. Some suggest a gradient method of going from busy on either your innermost or outermost layer to solid colors at the opposite end (e.g., a plaid blazer to a solid button-down or a polka-dotted shirt to a solid jacket).
2. Another method is using vibrant colors and busy patterns as accents in the same way you might use a pocket square or scarf. An exciting shirt peeking out from a v-necked sweater or the cuff of a jacket can go a long way in livening up a more conservative outfit.
3. Layering also allows for the possibility of change over the course of a night. By dressing down a more formal shirt and tie with a casual jacket, you can mingle comfortably at a bar before attending some stuffy business function. Conversely, pairing a blazer with more casual attire can elevate the ensemble, making it easy to go from a dinner-date at an upscale restaurant to gaming back home with a friend in one evening. We like to keep our options open.
As far as basic principles go, that’s about it. Blazers, sweaters, and button-downs are the bread and butter of layering, but experiment with all different kinds of clothing items. Take risks, develop your style, don’t overdo it, and remember:
Rules are meant to be broken.
For more detailed advice, check out the article by The Art of Manliness on the topic.