Easy, right? Not necessarily when you are thinking on the spot, you could quite easily find yourself start to panic and ramble on stuff that just isn’t relevant (and sometimes, not appropriate) to the employer.
What they do want is a clean, clear, concise snapshot of you (not fluffy your cat), but you, what makes you tick. Include your work history if you have some, if not, include some personal qualities that would make you a good fit to the job.
Have key points and words you want to include and go over and over and over again until it rolls off your tongue in a natural way, not like a rehearsed robot that stuck on the same track.
Including your passions is a great idea too, just make sure you can relate them back to the job and in a professional manner. Talking about your passion for horses because they have nice manes is lovely, but you could sell that to your potential employer by saying you are extremely passionate about caring for horses because you have compassion, commitment and responsibilities that brings you satisfaction.
You have made it to the interview normally after submitting your resume, so the company would have already seen something in you they like. Keep it true to your nature and interesting. You want to leave the employer with something that makes you stand out, make them remember you.
Main message: prepare and practice, practice makes perfect