File this in the "things I wish I had known" bucket. A mortgage or loan of any type is a big deal. Getting a low rate and eliminating loan closing costs are just the first part of the battle. Choosing a lender is the next. When it is time to do this, everyone will start giving you recommendations and you should do some work on which one you'd like to select. Here, I'll outline some tips that I will be using the next time I select a broker.
Eliminate choosing a broker that you know personally
At first this might seem silly, but when doing business I always try to avoid doing it with someone I know. "Business isn't personal" is the first thing that comes to my mind, but it's a lot harder to think that way if you actually know the person personally. If that doesn't convince you, ask yourself this: If something was done negligently, would you be able to sue this person for it?
Eliminate any broker that lies about anything
If the agent or broker lie about anything, even something as simple as "I did call you back and you didn't answer" and they didn't, dump them. If they lie about simple things, they'll have no problems lying to you about bigger things that can affect how much money you are paying them to the rate they have "locked in".
Eliminate any broker that doesn't call you back at a specified time more than 3 times
If a lender is too busy to call you back, or forgets to call you back numerous times, you've got a problem. As the loan process moves forward you are probably going to talk with these people at least once a day. If they don't call back when they need to you could set your loan back days, for no reason.
Eliminate any broker that has to get back to you on certain questions
Try asking questions that you already know the answers to. If the agent doesn't know, or needs to ask someone else and get back to you, get rid of them. This is their business and they are not fluent in it. You can tell that an agent knows what they are doing when they can answer your questions immediately without needing help. If you go with someone that isn't knowledgeable this could hold up your loan, and cost you money.
Eliminate any broker that gives you a bad feel
If you're getting a bad vibe from a agent, it's probably a good idea to not work with them. Trust your instinct, even if that agent is promising the world, if something triggers that bad vibe, get out while you can. Along this same sense, if you can, I'd suggest not going with a online broker, before doing business meet the person in person to get that vibe in the flesh.