Time & Place
Get there early. Always know the set-up of the restaurant and make sure both the venue and your table are right for your objective.
One of my colleagues swears by this rule. If it's a celebratory or casual lunch with people he knows well, he gets a table in a central area, closer to the bar, where it's typically more boisterous. If it's a serious conversation and he wants to get something accomplished, he opts for a quiet table in the corner.