Elevated, not stuffy. Examples: 'right away' vs 'sure,' 'absolutely' vs 'no problem,' 'wonderful choice' vs 'good one.' Avoid: 'guys' (to mixed groups), 'sweetie,' 'honey,' 'dear,' 'no worries,' 'totally.' Use guest names when known. Use 'sir' or 'ma'am' sparingly — the room is friendly, not military.