"Well, I am a strong communicator and am very effective in making sure the message I want to communicate is understood and received. I have great persuasion and negotiation skills and enjoy being around others, but am very flexible and can perform well on my own, and am very self-managed in my work. I am very resourceful, always am thinking outside of the box, and am very passionate about what I do."

What is important here is that you just be yourself throughout your interview. So you want to be just as honest with yourself as you are with the person you are sitting down with. So with this in mind, spend some time thinking about those strengths you take the most pride in. They are also likely to be the aspects of your work that you most enjoy. After all, when you are good at something, the better you feel about yourself when you are doing it.