Make sure that your original mortgage does not have a pre-payment penalty or early payoff penalty of any kind. Sometimes people will get into their mortgage with the mortgage having a pre-payment penalty and they will not even know about it. Pre-payment penalties usually range from 6 months to 3 years with a penalty for an early payoff. The penalty is usually about the amount of 6 months worth of your mortgage loan interest, but this varies. You would have to be able to have some significant payment and interest savings on your refinance loan to justify refinancing a mortgage loan with a pre-payment penalty.
Refinancing may not be that useful if you have already used up 90% or more of your home value in taking out a mortgage or any home equity loan. You won't be able to get the best rates available in the market as when you refinance a 90% LTV loan, you will probably require a loan of that value or higher. This will be quite closer to being a 100% financing option and hence mortgage refinance rates will be comparatively higher. Moreover, 100% loans are hardly available in times of mortgage market crisis.
Be Realistic. Lenders have tightened up loan requirements, so you'll need a good credit score and at least some equity in your home to refinance. To figure out how much equity you have, subtract the total amount that you owe on all of your existing mortgages from how much you think your home is worth. If your credit is severely impaired or you owe more than the value of your home, you probably won't be able to refinance right now.
Start with your current lender. If you're a good customer-you hold a sizable mortgage, pay on time, and maintain good credit-your existing lender will probably do everything in its power to keep your business. The company may cut you a break on fees for things like appraisals, surveys, and inspections if the information is current and you meet other requirements.