Buying a home is likely the most expensive financial commitment we'll ever make. The more homework you do before making an offer on a home, the more likely you are to stretch your mortgage budget.

Here are five ways to slash your mortgage costs:

Get pre-approved
Get pre-approved for your mortgage loan (not just pre-qualified).

With pre-approval, the lender pulls your credit report, verifies your income and takes other preliminary underwriting steps to come up with a loan amount. The lender also makes a written commitment to make that loan if a purchase occurs within a set amount of time. (In a pre-qualification, the customer provides verbal information, and the lender simply offers what might be a suitable loan program, with no commitment on the lender's part.)

Pre-approval requires the homebuyer to fill out a loan application and provide supporting bank statements, pay stubs, W-2 forms, and other employment information. There may be a small application fee, but it's worth it, because pre-approval puts you in the strongest possible bargaining position with sellers. Those who are motivated to sell a property often will accept a bid from a pre-approved buyer because they are more certain the deal will go through.

Consider an adjustable-rate mortgage.

ARMs feature lower monthly payments at first, that might help marginal buyers get into a home ... and the payments creep upward over time.

When you see interest rates going up, adjustable-rate mortgages actually become more affordable. People look for that lower payment, and ARMs can be one possible answer (especially if you expect to receive bonuses or a pay raise in the near future).

Interest rates for ARMs tend to be about 1.5 to 2 percent lower than the average 30-year-fixed rate. Someone borrowing $150,000 on a one-year ARM at 5.47 percent would have monthly payments in the first year of $849. The same-sized loan with a 30-year fixed-rate mortgage at 7.01 percent would cost $999 a month.

Balloon Loans
Balloon loans are another way to get a lower payment in the first few years. The buyer will be charged less interest upfront for a set time frame, but be required to either refinance at the end of that period, pay off the loan, or convert it to a fixed payment schedule.

On a seven-year balloon note, a borrower could make payments of principal and interest for that period of time. Assuming rates didn't increase more than 5 percent in the meantime, they might then be able to pay just $250 to roll the loan into a fixed schedule for the last 23 years.

Buy downs (this writers' favorite because the seller will pay for it)

If you have cash now, and want to lower your overall payments, you can "buy down" your mortgage rate. This is a good idea of you plan to stay in the home longer than 5-7 years.

It's a simple concept -- in exchange for a little cash upfront, lenders are willing to lower the interest rate, trimming back the borrower's monthly payments.

Trim closing costs
The interest rate isn't the only thing that determines how much you'll pay. Closing costs add up as well, so borrowers should try to minimize those, too.

Consumers should stick to a budget prepared BEFORE the emotions of househunting. Because the cheapest lenders could have the most conservative underwriting standards, home buyers could end up paying less in origination fees by showing a little restraint.

As an example, let's say you have $52,500 available for a down payment and want to buy a $150,000 home. You might be able to qualify for a loan with only $400 in origination fees because the cheapest lender writes deals for people who get mortgages for only 65 percent or less of their home values.

But if you also fell in love with a $240,000 home, you would be at about 78 percent loan-to-value. That's still conservative, yet maybe not enough for the cheapest lender. You end up finding another company willing to provide the money, and that company might charge $650 in fees.

So many people who want to pay top dollar for a house (for instance, in a bidding war, or with a "perfect" house) get into trouble. The cheapest lenders won't work for them.

This also applies to other factors, such as debt-to-income ratio. A borrower who spends 28 percent of gross monthly income on a mortgage should be able to obtain one more cheaply than a customer whose income reflects 35 or 40 percent toward their mortgage.

Consumers can take the Good Faith Estimate that they receive during the loan application process and compare it with those from other companies. For instance, If if one closing fee is $100 at one shop and $20 at another, but the second lender's deal is better overall, point out the discrepancy and ask the preferred company to lower its fee on that item.