'La bise' (cheek kisses) is reserved for friends, family, and existing relationships. Don't initiate with strangers or first business meetings.
In business, handshake first. After 2–3 meetings, if your French counterpart initiates bise, follow their lead.
Number of kisses varies regionally — 2 in Paris (one on each cheek), 3 in southern France, 4 in some areas. Watch and mirror.