1) have the details (and top level descriptions) of the work you have already done and put on your resume, on your fingertips. 2) Remind yourself of the obstacles you have faced in your projects and how you solved them - see that your explanations as to how you solved them will highlight the positives in you such as resourcefulness, creative problem solving, readiness to take help, determination, etc 3) If the requirements are for skills that you do not have, but think you can pick them up fast, figure out how your current skills and past exposure will enable you to quickly pick up tne new skills 4) Know the requiremetns very well so that you don't get any surprises 5) know your resume very well

If I were the interviewer, I would also ask (preferably through a questionnaire) a ton of questions to check problem solving capabilities and attitudes about different stuff.

Good luck and cheers.