Having endured a long, very cold winter last year without central heating (long story), I learned that layering is useful, concentrating on the coldest parts (head, neck, hands, legs, feet). For the body, several thin layers work better than a couple of thick layers, while a woolly hat and a separate polo-neck insert are good at keeping warmth in. Socks are difficult - thin ones don't keep feet warm, and thick ones mean shoes don't fit (either way, your feet have to be warm to start with - in my experience, they don't warm up cold feet, they just lock the chill inside). After tea, I have a hot-as-I-can-bear-it foot soak, then pull on knee-high fluffy slipper-socks for the rest of the evening.