Lenders like pristine credit reports. If you have a bunch of open credit card accounts that you never use (and who doesn't?), consider closing them. It will boost your credit score and make you a much more attractive borrower to a lender. Then, a month after you've closed your accounts, go over your credit report with a fine-tooth comb. It should read that the accounts were closed at your request. (You don't want lenders to think someone cut you off and that you're a bad credit risk.)
When refinancing a mortgage, as many as 30% of homeowner's cash out part or all of their home's equity. By investing in home improvements or paying off credit cards, this can be a smart. But, if you are borrowing more than 80% of your home's value, you will be hit with private mortgage insurance, costing you hundreds a year.
It's better to follow the 2% Rule which suggests that you can enjoy the benefits of a home refinance if your mortgage refinance rate is 2% lower than that on your current loan. The interest savings will help you recoup the costs you've paid for the new loan provided you stay in the property for a certain period of time (break-even period). However, there are no-cost as well as low-cost refinance loans wherein the costs are included into the loan. But you can expect comparatively higher rates on such loans. Moreover, these loans are limited when the market is in a credit crunch.
It is feasible to go for a refinance when you have built up at least 10% equity in your home (For Fannie Mae owned mortgages, the value is 5%). It is also possible for you to choose the option if your equity is less than 5%, but you may have to pay a certain amount of cash in order to make up for the difference in equity.
Mortgage can last a lifetime and that extra 1% can add up to literally thousands of dollars over the years. I have friends that are in their 70s and still paying off their home loans. It'll pay off in the long run to make sure you find the best deal possible. Don't let poor credit stop you from refinancing your home.