You cruise through Black Friday events on high and shop sample sales like a pro. How hard could this mortgage thing be, anyway?

Even if your shopping skills are stupendous, the stakes with mortgages are high. Tiny little differences in interest rates could mean tens of thousands or even hundreds of dollars more you'll have to pay over the 10-30 years you have your home loan.

And banks know you're shopping for the best deal, which is why they put their "door crasher" interest rates on their brochures, flyers, ads, and foreheads. The teeny tiny print at the bottom of the ad tells you that interest rates may vary.

And do they ever.

Sit down across from a smiling mortgage specialist at your local bank, and the rate you're quoted might not even be in the same universe as the rate lit up in lights outside the office.

What's going on? More importantly, how do you get a good deal?

The interest rate that banks quote in their ads is the "bait." That's the absolute lowest possible rate they're willing to offer (and usually don't offer). The goal is to get you in through the door so they can tempt you with visions of owning your own home—and so you'll sign on the dotted line.

There's no sample sale for mortgages (which is a good thing: who wants to be stuck with the leopard-print jumpsuit equivalent of a home loan?). But there are a few ways you can get the absolute lowest mortgage possible:

Getting a Good Deal

There's no sample sale for mortgages (which is a good thing: who wants to be stuck with the leopard-print jumpsuit equivalent of a home loan?). But there are a few ways you can get the absolute lowest mortgage possible:

• Know your numbers. Use online shopping engines like bankrate.com, quickenloan.com, or lendingtree.com to find out what rates are possible (and where).
• Put down a larger down payment. The more you can save up, the less loan you'll need. More money down also means a better rate.
• Pay down your debts. Walking into a bank with few or no debts is like blood in the water in shark country. Bankers want to do business with someone like that and will play ball (financially speaking) to make it happen.
• Improve your credit score. Pay down your debts, pay your bills on time, and fix any errors on your credit reports.
• Choose your house wisely. If the value of your house is much higher than the size of loan you're trying to get, you're a lower risk to bankers and they may cut you a deal.
• Work on that promotion. Having a good job with a good income helps. Even staying in your job and rising up in the ranks shows that you're a responsible adult and deserve a good rate (maybe leave out the fact that you like to watch cartoons and eat ice cream in your PJs).
• Take out a shorter term loan. If you can repay the loan in ten years rather than thirty, that means the bank can get their money faster and they'll be willing to charge less interest (maybe).
• Find people who will guarantee the loan. If your mom, dad, or granny are willing to act as guarantors, they're essentially saying they'll help out if you can't pay for some reason.
• Choose your mortgage carefully. Compare the rates on fixed-rate, ARM, and other mortgages. Which gets you the best deal?
• Think positive and repeat mantras. Make a wish for low rates when you blow out your birthday candle. It can't hurt.

Going in to get a mortgage is like going in for an interview for a really big job. Get ready ahead of time and bring in all the papers that show you can be trusted with hundreds of thousands of dollars.

Be sure to keep a straight face, too.