If you have bad credit, find a lender who is willing to work with you and offer you reasonable loan terms.
There are literally thousands of mortgage companies all over the country. It is important that you choose a reputable one. Most reputable companies will be part of the Better Business Bureau or other community watchdog group. Good companies will also have websites that rank well on search engines such as Yahoo and Google.
Use a mortgage broker. A mortgage broker will show you mortgage products from different banks and mortgage providers. Pick a mortgage broker carefully. If the broker works directly for a company that offers financial products, make sure he shows you clearly why one of these products is better. Mortgage brokers also get a commission on their sales. Find out what the broker's services include and if he charges any fees. Many brokers do not charge fees beyond their commission. Also check the broker's credentials.
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.
When refinancing, don't take the first offer that comes around. Instead you should actively compare both interest rates and lenders.