Summarize:

If you're really not sure where you're going with your answer, ask the interviewer to clarify what they're looking for. You might find that they specifically want to hear about your personality, or they may want to know the ins and outs of your last job. Be careful when asking for clarification. Don't say the question didn't make sense or that it's too vague. Instead offer specific things that may help guide your answer: "I'd love to do that, did you want to know more about my professional experience or my personal interests?" This gives a more casual start to your answer, and makes you seem like a more well-rounded person. Try and stick with hobbies and interests that you can link to the job opening, but always be authentic. Don't pretend to be interested in softball just because the interviewer has a little league trophy on their desk. For example, if you're applying for a job in the finance sector, it's a good idea to talk about your personal investments. This is especially important if you have a particular cause you care deeply about; it adds another level to your character. Focus on specific tasks you had as a volunteer and mention your best accomplishments. This is crucial if you don't have a lot of work experience. Volunteer experience can help you put emphasis on qualities you want prospective employers to know about. Whether you worked in a soup kitchen or organized an entire fundraising event, most volunteer experiences can be a great opportunity to outline your strengths. More than anything, the way you frame your professional history will show how fit you are for the job. This is your chance to reference skills that are relevant to the job opening and show how you handled difficult workplace conflicts. Always make sure to spin these situations positively. Don't make the mistake of saying you didn't learn anything from a previous job. You should be able to draw a lesson from any work experience. A great way to spin workplace conflicts positively is to focus on the concrete actions you took to resolve it. Did you go to your boss, respecting the chain of command? Or maybe you proposed the perfect compromise? Answering the interviewer's question with rapid fire facts is sure to bore them and make you seem uninteresting. Use lighthearted humor that's relevant to the conversation; don't go into a monologue about your dog. The key is to use humor to offset situations where you're doubtful or uncomfortable. For example, if an interviewer asks if you'd have a problem with working weekends, you can answer something along the lines of: "I can't miss Sunday night football!". Then mention that you're kidding, and outline examples where you sacrificed weekends for work. The whole reason you want to prepare your answer is to avoid hesitating when the question comes. You want to show whoever's asking that you're confident and self-aware enough to answer their question quickly and efficiently. Confidence in job interviews is something that comes with time. Until then, "fake it till you make it." Think of yourself as a confident person and you will become confident. Keep your answer to 60 seconds tops. Otherwise you risk rambling and making the resulting answer unclear.
Don't be afraid to ask for clarification. Start with your interests outside of work. Use volunteer work to your advantage. Go into your previous work experience. Keep things light with appropriate humor. Respond quickly and confidently.