7 Use throw rugs on hard wood floors. They don't have to match, they don't have to be expensive, yet they will warm up your feet and insulate from the floor up.
8 Plug the unused chimney. If you don't actually use the fireplace, install a chimney plug to prevent air from escaping. If you use your just-for-looks-flip-the-switch gas fireplace, know that it could be costing you a fortune and not really emanating much heat.
9 Hang blankets over the inside of windows. This is not the most attractive option, but smart people choose shabby over chic if they're battling serious heat loss.