I review a lot of portfolios. It's what I do for a living. And the single biggest mistake I see in those portfolios is that people don't show the kind of work that I'm hiring for. As designers, we are trained to take the client's needs in mind when we are creating new work. What most of us fail to do, however, is to keep those same needs in mind when putting together a portfolio. What follows are based on my notes from the presentation I gave in April at the AIGA Minnesota 2009 Portfolio One-on-One.