This is going to be a bit long and detailed
Research the Company
You can never know too much (especially of a place you’re yet to experience). Scour the company website thoroughly, reach out to your potential colleagues (LinkedIn helps an awful lot), #hannytalker
Arrive on time and dress well. You can never go wrong in business corporate.
Maintain a Positive Outlook. Smile, and maintain good eye contact with your interviewer(s). It passes you off as a confident person.
Thank the interviewers before leaving and if possible send a thank you mail. #hannytalker