Some evenings call for nothing more than the sofa. A proper night in takes about ten minutes of setting up, and most of it costs nothing.

Get warm first
Fill a hot water bottle before you sit down. Let the kettle cool for a few minutes rather than using boiling water, fill it no more than two thirds, and squeeze the air out before you put the stopper in. Our faux fur hot water bottle is £11.99 and made to British Standard BS 1970.
Keep a blanket within reach
Leave one on the sofa so you're not hunting for it. The Royal Stewart tartan blanket is £24.99 and big enough to share.
Low light
Lamps on, big light off. A candle if you're staying in the room.
Something warm to drink
Tea, hot chocolate or a small whisky. Whatever counts as a treat in your house.
Phone in another room
The hardest part. A book, a film you've seen ten times, or nothing at all.