This is why it's time to warm up with five sensible window insulation tips to guide your best efforts. What if you're still skeptical about your ability to insulate your windows? Look at it this way:

If you've ever written someone's name on a cake with a tube of frosting, you can apply caulk to your windows. If you've ever sealed an envelope with tape, you can apply weather-stripping. If you've ever wrapped a birthday present, you can create a makeshift double-pane window. And if you get stuck at any point along the way, professionals are ready to assist you – so that you truly feel like you have the wind at your back as you face your window insulation project.

Identify cracks, gaps and holes

Identifying cracks, gaps and holes in windows is often the step that many homeowners fret about most. After all, what if they overlook a problem spot?

Fortunately, there are several simple – and downright fun – ways to ensure you identify each and every weak spot.

First, wait for a somewhat windy day to inspect your windows. Then run a smoke pen or even a feather or long-stemmed lighter around the perimeter. Any signs of movement will point to a crack, gap or hole.

Mark it immediately with a piece of paper or a sticky note. Then verify the leak by waiting until dark, turning off the lights in a room and shining a flashlight around the window. The leaks will come to light – literally.

Distinguish caulk from weather-stripping

Once you know where your windows need to be sealed, you might well be wondering which remedy is better – caulk or weather-stripping.

The U.S. Department of Energy demystifies the question with this helpful tip: “Use weather-stripping in your home to seal air leaks around movable building components... For stationary components, caulk is the appropriate material for filling cracks and gaps.”

Caulk and weather-stripping are readily available at most home improvement stores. It always pays to read the instructions first, before collecting the tools you'll need: rags or paper towels, a putty knife, a measuring tape, a pair of scissors and a plastic bag to dispose of waste. Then clean the window and dry it completely to foster a tight grip.

Apply caulk with confidence

It's smart to practice working with a caulk gun before going to work on your windows. (Try applying caulk to a scrap piece of wood or piece of cardboard.)

Hold the gun at a steady, 45-degree angle. Try to squeeze out the caulk in one steady stream rather than a series of stops and starts. Once you feel comfortable, wait until it's at least 45 degrees Fahrenheit outdoors and:

  • Direct the caulk to the bottom of a crack, gap or hole to prevent bubbling

  • Apply a thicker, rather than thinner, layer of caulk to be certain you've thoroughly insulated a window

  • Steer any errant caulk into place with a putty knife

Apply weather-stripping with a sure hand

While it's oh-so-tempting to unroll weather-stripping around a window and then make the cut, you'll actually get a better fit by measuring the window and then cutting the weather-stripping to size – plus an extra 2 inches, just to be sure.

Weather-stripping can be applied in colder temperatures than caulk, but it should be at least 20 degrees Fahrenheit outdoors. Secure the weather-stripping between the sash and frame, ensuring that it doesn't block the proper operation of the window.

Make a double-pane window – and other moves

Not even a window that appears to be gaping or that really should be replaced should give you pause at this point; you've mastered the essentials of window insulation and are up to the task of making a temporary double-pane window with clear plastic or vinyl sheeting.

Secure the material with weatherproof tape or duct tape, trim or tacking strips. Otherwise, purchase shrink film and use a hair dryer to affix the film over the window.

For good measure, you also can block cold air from seeping through your windows with:

  • Cellular shades

  • Layered curtains

  • “Draft snakes,” or those decorative fabric tubes that many homeowners also place along drafty doors. (If you're handy, you can sew your own tube after measuring the width of your window and then filling the inside with dry rice.)

If you're sweating the finer points of insulating your windows, or simply want reassurance, contact a professional. Following these window insulation tips will make your windows as airtight as they can be – so that your insulated windows can give the onslaught of air that wants to rush inside the cold shoulder.