Winterizing my apartment to save money

There are many aspects of the cold weather that I like... drinking copious amounts of hot tea, watching snow fall before it gets dirty from foot/car traffic, winter accessories... I could go on. But one thing I don't like about the cold weather months is how my energy significantly spikes as the temperature falls. To avoid getting sticker shock every month when I look at the energy usage on my Pepco (the name of the energy company here in DC) bill I do the following:

• Seal my windows with plastic to prevent cold air from coming through the cracks. I absolutely love my apartment, but my windows are a bit drafty, so this is an easy way to prevent the heat from escaping.
• Lay a towel down by the crack at my front door to prevent the cold air from sneaking in. After all, I'm not paying to heat the hallway! Maybe eventually I'll find a more stylish option to block the door draft, but for now a towel or old pillowcase work just fine.
• Keep the heat temperature relatively low (no higher than 65 degrees) and just use a space heater to get the room a comfortable temperature. I also only need to heat one room at a time.
• All year-round I try to only turn lights on in the room I'm in at that given time. I love light, but it's kind of silly and a waste of money (and energy) to have every light in my apartment blazing when I'm home.

I do use budget billing for my Pepco bill because I like knowing how much my payment will be each month, but if my usage spikes significantly, my monthly payment can be raised, so I really try to monitor my usage year-round. These small steps make me more comfortable indoors and help me to manage my energy bill.

Do you have small tricks you implement to winterize your home?