What you wear and what you look like for an interview has a huge impact on the impression you make. Try to make your looks fit the company culture, so the interviewer can actually picture you working there. If you are unable to determine the corporate dress code, wear formal clothes, without overdoing it.
Do not smoke or drink alcohol before an interview. Do not use heavy perfumes.
Preparing for an interview also means knowing how to get there on time. If you go by public transport, check the timetables and beware of possible delays. If you go by car you should be prepared for traffic jams.
If you leave a bit too early, you won't have to stress if something goes wrong. Ideally, you'll arrive on time and you'll have time to sit down, relax and run through a few things before the interview.
Avoid rucksacks for job interviews, since they can be inconvenient and can make the sharpest suit look sloppy. Instead, bring a portfolio, containing
- a double copy of your cover letter and CV
- blank paper for taking notes
- the job ad
- a professional-looking pen
If you get an invitation for an interview, it is not enough to put on nice clothes and wash your hair. All the other candidates will look just as smart as you and will have comparable CVs. Of course it is important to be on time and be well-dressed, but this is not the way to make the recruiter remember you.
To stand out from the crowd, you'll need to fine-tune your interview techniques. The best way to practice these is by going to job interviews. It might be hard to accept, but bad interviews are valuable too. You will never make the same mistake twice.
Mock interviews are a somewhat safer way to practice your interview skills. A good interlocutor will be able to prepare you for different interview types and different kinds of questions. If you have a camera or another recording device, you can judge your performance more objectively.