You better shop around. For a mortgage.

So many potential home buyers don't compare prices for their mortgage, and it's a huge mistake.

I shop around for everything from cars to soap. Why wouldn’t I shop around for my mortgage?

It seems like such a common-sense thing. Different banks offer different rates on their mortgages. They also have different amounts on their closing costs. Finding the best deal among many offers makes a lot of sense.

So often, though, when I talk to readers who have recently gone through the home-buying process, the single most common mistake I hear about is that they didn’t shop around for a mortgage. They looked at some rate advertisements, applied for one of them, and ran with it.

That’s a mistake. Shopping around for a better mortgage deal will usually save you significant money.

At what point in the process do you shop around? I suggest shopping around before you even begin seriously looking at homes. This way, you can be pre-approved before you move forward. You’ll also obtain a good faith estimate of the costs associated with each loan.

Should you apply for every loan under the sun? There’s no reason to do so.

Start off by doing your homework before you apply. Know exactly what type of loan you’re looking for before you ever go near a bank. I would strongly urge you to avoid adjustable rate loans, as they often tend to adjust at an inconvenient moment in your financial life. Stick with a thirty year fixed loan unless you’re sure what you’re doing (or, even better, a 15 year fixed).

You’ll also want to filter the banks you apply to. You may prefer to go with a local credit union or a local bank because of the convenience of the service, or you may be fine with simply basing everything purely on the advertised rates (using a service like Lending Tree).

This might be a good time to check your credit report. The federal government makes this process pretty easy. Just make sure that your credit report has nothing on it that’s incorrect and damaging to your credit, as lending institutions will examine your credit report to determine the interest rates they’ll give you. Although most lenders use a similar model, some lenders are more forgiving of questionable credit than others.

In my own experience, tapping your social network can do wonders in situations like this. You can often find pointers to responsive lenders, as well as lenders to avoid.

It’s important to note that rate isn’t always the ultimate answer when it comes to which lender to use (although it’s a pretty big factor). Lending institutions with poor customer service reputations should be avoided. For example, my own home lender routinely failed to make correct payments out of my escrow, causing me to be late on property taxes and homeowners insurance. After that, I had to call both the lender and the institutions multiple times each time a payment was due. It was a significant hassle that would have made another lender more preferable.

Shop around for your mortgage, just like you’d shop around for a car or a DVD player. Your checking account will thank you.

This post is part of a yearlong series called “365 Ways to Live Cheap (Revisited),” in which I’m revisiting the entries from my book “365 Ways to Live Cheap,” which is available at Amazon and at bookstores everywhere.