No flats, no sling heel. Shine them or buy new. Take several fresh original resumes. Nice pen and portfolio for note taking. Be prepared for the interview in terms of knowing the company, knowing about the position, rehearsing answers to questions you could be asked, and preparing questions you want to ask.
Role play mock interviews to build confidence.
Be prepared to sell yourself. If you don't, no one else will. Be prepared to address your weaknesses and face them head on. We all have strengths and weaknesses. Arrive 10 minutes early.