Cheaper pipe insulation

If you need insulation for your water pipes, check the difference in specially formed pipe insulation and regular sheet insulation. You can cut strips of sheet insulation and wrap around pipes, holding with duct tape and it works just as well.

Foam insulation for electric outlets

You don't need to buy precut foam to put behind the electrical outlets to keep the cold air out. Save a few of those foam meat trays, cut them to size and insert like you would the kind you have to buy.

Stop the cold from entering

If you need to fill in a crack or hole around windows or doors, use papier mache. Newspaper is a good insulator, so papier mache will help keep out the cold or heat better than caulking.

Press it firmly into the crack with a hard object. It will take a few days to cure, so choose a warm spell if you can.