Beth Allen -- the author and blogger behind DIY Hip Chicks -- says doors and windows are the biggest culprits for letting warm air out, cold air in, and increasing your heating costs. But you can fix those trouble spots without spending a lot of money.
"There's a whole pile of products that you can use, from weather-stripping to caulk, that are inexpenisve and easy to apply," Allen explains.
You just don't want to wait too long.
"Some of these products, you have to apply in temperatures above 40 degrees," she ays. "So you can't wiat. If you start waiting until mid-November or December, you're out of luck."
If your windows are really leaky, you can basically shrink-wrap them with plastic sheets that you tape up around the edges and then seal with a blow-dryer. Frost-King sells kits that start at $8.
Or, you can run clear caulk -- that peels away in the spring -- in any gaps between the upper and lower panes. Dap sells Seal'N'Peel removable caulk for about $6.
For doors, you can apply stick-on weather-stripping around the frame. Just make sure it's not too thick, or the door won't close properly. Prices start around $5 a roll.
To get more of Allen's tips on inexpensive ways to winterize your home, click here and check out her blog.