antss beat me to it. Go to the NKBA website and do a search to find a KD in your area. If you're in Portland (I am), a search turns up quite a number of choices.
I asked a friend of mine, a CMKBD in another state, for advice on how to find a good kitchen designer. She suggested that I start by checking the extent of their experience and knowledge, often designated by AKBD, CKD, CMKBD (see link) after their names. However, there are designers who have the skill and knowledge base who haven't undergone the testing to receive the above designations so she suggested I also check how many years they've been in the business, the type of projects they've done, what other designations they have, and their work portfolio.
Beyond that, I also check their rating with BBB and Angie's List (wish they had a category for kitchen design) and I do a Google search to see if I can find additional information on them. Some designers have a pretty healthy on-line status while others barely register in a search. That's not to say that the former is better than the latter. I found an excellent seamstress via word of mouth who has no on-line presence. Check references, too.
Another place to meet KDs is at the Portland Home & Garden show (starts today, runs through Sunday) although I think I had better luck meeting KDs at Portland's Home Improvement and Remodeling Show but that's in the fall. There's also the Tour of Remodeled Homes coming up in a few weeks. I've met a few designers that way. Sometimes they are part of a design/build firm and the only way to work with them is to hire their design/build firm but I've also met independent designers on the tour. In fact, I met one last spring whom I'm considering hiring.
If I haven't already met someone I'm considering hiring, I call to chat to get a sense of how well we might work together.
I have hired a KD once already but it was a disappointing experience. I saw her work (she designed a friend's kitchen) and she came highly recommended so I had high hopes but it was not a successful partnership. All I wanted was for her to trouble-shoot my design. I have already spent a lot of time planning my kitchen, considering multiple options for more than 2 years. She insisted that she should start from scratch, bringing fresh eyes to the task. I agreed. $500 later she offered me 4 designs, 3 of which included elements that I had told her were no-gos (for instance, she eliminated my walk-in pantry). The 4th design was the same exact lay-out that I had started with. I wish I had remained firm on how I wanted to work with her. So my final bit of advice is to be clear about your expectations and what you want the designer to do for you. Unless there are compelling reasons not to, stick to your guns.
Good luck!
Here is a link that might be useful: NKBA Certifications
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