How to Answer Interview Questions Effectively
Treat this exactly the same as you would answer if the question was asked in an interview. The best way to answer a question like this, both orally and in writing, is to relate it specifically to the job you are applying for. In other words, use this as an opportunity to drive home your claim to the job. Talk about your skills and experience as they relate to the position. Nothing else is relevant. Don't discuss education, hobbies, or any other extraneous topics. Keep it strictly to the point.
If the job description mentions problem-solving, client service, and a high level of organizational skills, then use this opportunity to briefly discuss yourself in relation to them. You are still discussing YOURSELF but in terms that relate to the job. It also demonstrates to the employer that you have seriously considered the question.