Although interviews vary from role to role, generally the process is very much relaxed and easy. We advise that all candidates attending an interview are formally dressed unless otherwise stated, and most importantly, believe in yourself.
Just be honest and show integrity with a willingness to work
Be well spoken and ready to responded when required. Treat everyone with an equal opportunity.
Put some clothes on. Any clothes will do; as long as your unmentionables are covered. Don't worry too much about technical stuff such as washing or brushing your teeth, unless you're going for a senior position. Also, research the entire history of the company you'll be working for and make sure you get 100% on the questionnaire, because what good is 99.99%? Would you trust a 99.99% surgeon?
Ask questions and make sure you are able to understand what they are explaining
Find out about the company, arrive early and greet with a smile
Research company and role.