Things that have made a difference for us:
another vote for oodie style things. Ours are kuddly brand, they are going into their fourth winter and still look good as new despite extensive wearing and washing. We got 2 for £50 and they have more than paid for themselves.
Last year we bought heated throws for the sofas. Means that we can have central heating on for shorter durations, and often on lower when we do use it. We got ours in costco, and they were an exceptionally good buy on the black friday offers.
brushed cotton sheets on the bed and lots of thin sheet / blanket layers to trap the heat rather than just one thick layer. Hot water bottles put in to bed at least 30 mins before bedtime - wrap your pjs around them so that you are warm getting into bed.
candles and battery operated lights create an ambience that makes a room look warm and cosy.
Draw curtains as sun starts to set to keep ambient heat in room.
Leave the oven door open after cooking so that heat can escape into the house.
lots of hot drinks. On days when I'm home for the day, I fill and boil the kettle and transfer the spare hot water to a flask so I don't have to keep reboiling the kettle throughout the day.
decent slippers / slipper sock to prevent heat loss through feet.
A hot element with all meals (e.g. instead of just a sandwich at lunch, I'll have some soup too).
the back of our house (where our dining room is) is south facing, whilst the living room is north facing. In winter, the back of the house is noticabley warmer than the front as it gets more sun. We have set our dining room up with a sitting area so we can make use of the ambient warmth in there