Weigh the costs carefully of how long you will be staying in your home vs. how much of a savings you will be getting in a refinance. Make sure you include closing costs in your decision.
When it comes to lowering your rates you will need to weight the benefits of having a lower rate vs. paying points up front. You may end up paying a lot more depending on your choice and how long you plan on keeping your mortgage.
These days most people request a Good Faith Estimate (GFE), but have no clue what to look for on the GFE. Make sure you request a GFE that has ALL fees estimated and disclosed. This includes: origination points, processing, lender, appraisal, title, escrow... ALL FEES... especially the Yield Spread Premium or YSP.
Give yourself plenty of time to close. With most refinancings, your file is turned over to a closing or title company, which dictates the closing details. Like the lenders themselves, these firms are swamped when interest rates are low. Moreover, appraisers get backed up and can be difficult to schedule. So don't expect the closing to happen as quickly as anyone promises.
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.