A breeze blowing through your house is a good way to keep things cool – unless, of course, it’s coming from a fireplace damper or other leak when you’ve been running the A/C running on high.

A home energy audit can help you pinpoint these air leaks (and other costly energy drains). And, good news, it doesn’t necessarily have to be done by a pro.

With a flashlight, some simple props and a good eye, you can conduct your own audit and uncover problems that, when fixed, can help conserve energy and save money in the cost of operating your home (there are also energy tax credits that can help defray the cost of any improvements).

Step one, of course, is getting the home energy audit done. Here’s how:

Review your energy bills. If you’ve been in your house a while, gather the last 12 months of utility bills (homebuyers can also gain good intelligence by asking the seller for this info).

Take a look at your usage over time. Has it gone up? Were there any spikes? How much are you spending? Getting a firm handle on these measurements will put things in context and set a baseline for improvement.

Uncover any drafts. From here, you’ll want to identify the air leaks in your home. You likely know where the big ones are (that draft from under the front door can’t be ignored!), but there are less obvious culprits as well.

Here’s how to spot them: Tape one end of a small piece of plastic wrap to a pencil, and let the rest hang free. Walk around the house and see if your sensitive “flag” moves in certain areas of the house. If it does, you have a draft.

Check baseboards, window frames, doors, fireplace dampers, mail slots, and the holes where pipes pass through. Be sure to visit the basement, crawlspace, attic, and outside spots like house corners, where the chimney meets the siding, and where the foundation meets the siding.

Keep a checklist of everything you encounter. The typical solution for an air leak is caulk, spray foam or weather stripping; your local hardware store employee can also help with ideas if you’re unsure of the best approach.

Look for insulation. Next, you’ll want to assess your existing insulation; the loss of hot and cool air from the ceiling and walls can be major. And, if your home is older, you simply may not have enough insulation.

Start with the attic. The structural elements are typically exposed here, which makes it easier to spot the insulation (and to add more in if what you find is deficient).

Exterior walls are more difficult to inspect, but you can try this tip: turn off the power to an outlet and remove the cover; you should be able to peer inside to see if there’s insulation inside your walls. Try this on multiple outlets and, if relevant, on multiple floors to get a whole-house perspective.

You’ll also want to check for insulation under floors that sit up against an unheated space (like a basement) and on all your pipes: If water pipes run through unheated or uncooled spaces in your home, they should be insulated.

Once you have an idea of how much insulation you have, you can compare that against the recommended R-value of insulation (a measurement of effectiveness) for your area, and make a decision on whether you need to add more.

Check your cooling and heating systems. Since up to half of a home’s energy usage is directed toward heating and air conditioning systems, heating and cooling efficiency is especially important.

Check furnace filters (you should replace them every month or two, especially during periods of high use). If the ductwork has dirt streaks, especially near seams, it may indicate an air leak that should be sealed with “duct mastic” (a puttylike material).

If yours is an older unit (more than 15 years old), consider that a newer furnace can greatly reduce your energy consumption.

Swap out your lighting. Lighting is one of the easiest areas to fix in an energy audit. High-wattage bulbs (such as 100 watts) are expensive to run, so you’ll see your electricity bill drop when you replace them with lower wattage bulbs or, better yet, when you swap them for CFL bulbs. Compact fluorescent bulbs use less energy and often give off just as much light as regular incandescent bulbs.

Of course this all takes some initiative, and getting a professional home energy audit—and the infrared scan and blower test that typically comes with it—may be the better option for some people, it’s good to know that an audit can quickly, inexpensively and pretty accurately be done on your own.

Either way, it’s important to remember that the savings of a home energy audit won’t actually kick in until you implement the improvements!

Guest blogger Pauline Hammerbeck is a content editor for The Allstate blog, which helps people prepare for the unpredictability of life.