Posts above have already mentioned eye contact etc. A interview however daunting it may sound is supposed to be a two way conversation. I had one the other month. Started off talking about weather which went to working on cars and then we talked about cars for about 10 whole minutes lol. interviewer said how she had problems with saxos and I just knodded my head and talked about my project etc.
Every two people on the face of the earth can relate to each other in minimum one senario, some two people have same birthdays, maybe life experiences, maybe job role etc so you have to figure out the common ground and talk about that.
But lol, forget about the above, just go in there, be confident, smile, laugh, but don't do it all at once and also ask questions about the role, about the company, do plenty of research on the company so when they ask you "what do you know about us" you'll have an idea of what to say.
Just hope for the best, act natural, don't be unbelievably polite as saying thank you every 10 seconds, don't lie.
These are the things that have helped me in the past, You just have to be on the "same wave length" as your interviewer.
Relax
Also compliment on the restaurant build and say it's very nicely built out etc.