Throw an extra blanket on the bed and wear a wool sweater if you home feels chilly. You'll be warm and toasty before you know it. Circulate heated air, since warm air rises, it tends to be trapped in the highest areas of your home. A ceiling or portable fan running at a very low speed can help distribute warm air more evenly and reduce the desire to turn the heat up. Keep drapes and blinds closed.
Drapes add an extra layer of insulation.
If you don't need the outside light, leave them closed. Mini-blinds also insulate, but to a lesser degree. Turn louvers down toward the ground outside. This diverts rising heat back into the room instead of trapping it between the blinds and the window. Check heat ducts for leaks.