Keeping Warm in Good Times

It's really cold. It has been in the teens or lower for days now. The apartment complex put up signs asking everyone to keep the cabinets open and faucets dripping so the water lines don't freeze. Our apartment is doing okay, the furnace comes on only every couple of hours, which I think is good.

There are some cold spots:
The front door but it is lots better after adding some extra weatherstripping. Now it only leaks a little at the top corner.
The balcony door is mostly glass so it has hardly any insulative value whatsoever. It's a double pane but it an aluminum frame so worth maybe an R6, tops. Sadly, all the windows are like that.
There is cold air back-feeding into the drier so the laundry is a little on the cool side. If we don't put the clothes out right away they end up very cold.

What's working for us:
The bedrooms are staying pretty warm, we have heavy curtains and bookcases on the outside walls. The air leaking around the bookcases is quite cold.
Extra weatherstripping on the doors helps as does a heavy curtain.

Other ideas
We have a fire place but not much fuel handy.
In case of a power outage, we could hang blankets around the master bed to make bed curtains. Like the four-poster beds used in Victorian times to stay warm.
We could still add a layer of plastic over the windows and felt on the walls for extra insulation.

Until very recently, most homes have not been very well insulated. Using four-poster beds and wing-back chairs to minimize the effects of drafts were effective but didn't attack the problem. Nowadays we can wrap whole houses in wind resistant material which makes a huge difference. Some people even complain about we are making houses too air tight and there is a problem with indoor air pollution.

Well, if your home is nice and tight we have control, aka open the windows when the days are warm and close them when they are cold like now. We also should make sure the products we bring into our homes don't pollute our own air and we can use plants that clean the air in our homes as well.

A good home design is more then the sum of the checkboxes ticked in MLS. It is how it all works together.