A few pointers to consider before meeting somebody for lunch interview.
Do some background checking online who you are meeting and make sure you have their phone number.Be sure you know the place and be punctual. Better be overdressed, adapt to the restaurant. Firm hand shake for greetings, eye contact and smile. Table manners are important, chose something easy to eat (not spaghetti), neither the cheapest nor most expensive. The food is secondary. Keep off alcohol.
Have a few light chit-chat topics ready from the news, sports, hobbies, food talk etc. Do not feel though you need to filling in the silence gaps all the time. Smile a lot and when talking, look at the person in the eyes.
Practice brief introduction about yourself, why you moved here and there, milestones
⇒ Help them understand you better.
Key strengths vs job criteria
Highlight these and give example briefly with figures to back up if necessary
⇒ Help them assess the match
Think through your expectations as not to be taking by surprise if they talk about these. Do not open this topic first. If questioned, be vague, get them to put down figures down first. Ask for package details etc
⇒ Flexibility without closing nor breaking
Prepare questions as if you were meeting a company for first time as a consultant.
⇒ Show motivation and intelligence
Ask for next steps before departing
Send thank you email