Contracts provide mutually beneficial protection to both you and your photographer. Your photographer should send you a contract once you’ve both decided to move forward. The contract should define studio policies, payment and deliverable schedules, and contingency plans. Read the contract before signing; don’t make any payments until the contract is in place.
When styling a photo session, I like to start out with a basic color palette and go from there. It can help to have one “rock star” in the photos who carries a pattern in their outfit that the rest of the group’s clothing or accessories pulls from, while keeping everyone else’s outfits more simple. You can do this with a neutral and a few colorful brights, or try a softer palette that has different tonal ranges of the same shades.