Curtains at the doors, homemade draft excluders, not being allowed to leave the doors open for more than a second, some sticky tape stuff around the windows, having to wear lots of clothes especially cardigans, lots of heavy bedding, flannelette sheets.
We still do all of this! Live in a mid 19th century stone built house in the middle of nowhere. I was up the stairs putting stuff away this afternoon wearing several layers, inc two thick fleeces, a neck warmer, hat and wrist warmers. I made the wrist warmers out of an old pair of cashmere socks where the heels had gone. So I snipped off the bottom bit and I roll them up my wrists and lower arms. I do typing work at home so it also helps with dexterity.