Narrow down the pool by reading past reviews
and carefully studying their portfolio so you get a feeling of their specialty, technique, and process. Have a detailed checklist on hand and answer questions such as: Do they have a team of assistants, or do they work independently? Do they offer videography services, and are they qualified to fly a drone for aerial shots? Do they shoot analog, digital, or both? How do they make everyone feel comfortable in front of the lens?