If you've been putting off a price increase for a long time and the gap between your current prices and where they need to be is significant, don't try to close it in one go. Break it into two or three stages over 12 to 18 months. You'll get to the right price point without the drama of a single large jump.

Also: try to avoid raising prices immediately before or after something that's already put customers in a bad mood — a menu change they weren't happy about, a period of service problems, anything that's already tested their goodwill. Time your increases for periods when things are going well and customers are feeling positive about you.