Research, research, research…
Whether it’s talking to people you know that work at the company or doing a search online, you’ll need to do your research if you want the interview to go well. Potential employers will be impressed if they can see you've done your homework. If possible, it’s also good to try and find some information on the people interviewing you, with LinkedIn a good place to look them up and see what their role in the company is.
If you aren't told who's going to interview you, you shouldn't be afraid to ask either your recruiter or the contact at the company who this is going to be.