I have a process that clients go through before their photo session. I keep track of my client onboarding process in my customer relationship management (CRM) tool.
I must first see that a client has paid their booking fee. This lets me know that they are serious about a session. Then for the higher-value portrait services, I have them complete a questionnaire. That lets me know they are thinking about and hopefully excited about their pre-session consultation.
Then I'll send recommendations about how to prepare for their photoshoot. I can see through my CRM if they've opened this link and in my experience completing all these means they're ready for their pre-session consultation which prepares them for our photo session.