You should be able to discuss how your skills related to the fields that are of interest to you. Preparation is key to interviewing well. If you've had several first interviews and no follow-ups, it may not be that you're a bad interviewee, but rather that you're looking for a position which is not a good fit for you. Know which skills you'd like to develop. Everyone in today's workforce should develop a portfolio of skills.
Employers are interested in candidates who want to grow and develop professionally.
The more versatile you are, the more employable you become. Make sure your resume is targeted to the employers who will be receiving it. Make more than one resume if you are applying for more than one type of job. Learn how to talk with people about yourself and about themselves. To job hunt effectively you must be comfortable in conversation with others.