You should check references and ask for quotes in writing. A good broker will also be affiliated with a number of lending institutions. An established company with a good reputation will get courted daily by institutions after certain clientele - great credit, high-net-worth, sub-prime, etc. That is not to say that the broker with the most affiliations is the best but the number of available lending institutions is a good indication of how established the broker is. When you find a
mortgage broker you feel good about, investigate them thoroughly. These days it's too easy for scam artists and crooks to pass themselves off as financial experts.
Check references carefully. A good mortgage broker will be on your side from the very first meeting until the day the loan goes through. He or she will carefully record all of your financial information and then advise you on the best way to proceed. Ask your real estate agent for the names of brokers with good track records in the field. Check the qualifications of your broker, even ask for references from previous borrowers.