A proper appearance and an adequate outfit are essential for every job interview. You should dress appropriately for your future work environment (not just salesmen wear a tie). The first impression is crucial! Therefore, you should be on time. Should you be delayed, please call us immediately. Read up on your potential future employer (e.g., on the internet). Think of the reasons why you would like to work for exactly this company and consider what qualifies you, in particular, for the position that needs to be filled.
When you prepare yourself for the interview, anticipate questions that refer to your resume (e.g., area of responsibility, motivation for job changes). Keep answers and reasons ready – but do not expect a hidden agenda behind every question. Be yourself and maintain a natural charisma. There is no reason for being nervous: after all, you have been invited – you have already passed a first preselection.
Listen carefully, and do not hesitate to ask if you have not understood everything. Ask questions occasionally – but do not interrupt the interviewer. Seek eye contact during the conversation. This signals candor, trust, confidence, and shows that you do not have anything to hide.
Express yourself naturally, matter-of-factly, and in clear words. Do not talk too much, and only give answers to questions that you have been asked. On the other hand, provide sufficient and adequate information so that the interviewer does not have to "dig any further."
Do not talk negatively about your current employer, superiors, and colleagues. Do not let spontaneous negative impressions discourage you: even if the personnel manager is not quite to your liking, you have to keep in mind that they are not going to be your day-to-day superior – who may be the exact opposite!