I think the only way to get a good architect is referrals. You can get referrals in a lot of ways though. First ask neighbors and friends who live in your area who you know have done projects. Write down names of architects on yard signs in front of on-going projects in your area. Also, post requests for recommendations on listservs or blogs that you subscribe to. I received a lot of recommendations through my local mom's club, Mothers of North Arlington (MONA). There are also several larger firms which are well-known in our area which I also added to the list although these were generally design/build firms.
These recommendations yielded a list of about 10 architects to consider. We called and emailed about 8 of these and then set up in-person interviews with about 6 architects and design/build firms. We were able to narrow from 8 to 6 based on the telephone conversations or lack of return communication (not the way to do business!). We then interviewed each of these candidates which included one design/build firm which came highly recommended. We liked certain things about all of them, but ultimately we went with the person who we thought would give us a lot of attention, had some creative ideas, and who would also listen to our ideas. She also doesn't work for a large firm so her hourly rate is very competitive. She gave us 8 or so references (with addresses and phone numbers). We spent a Saturday morning driving by several of the houses that she worked on and all of the additions were beautiful. She also worked on a neighbor's project which was very similar in size and scope so we were able to see that project as it was going up last winter and get a lot of feedback from our friends. This gave us additional comfort because she had to be very current on the constantly changing Arlington County codes.
Please feel free to comment on how you found your architect.