The date is booked and the shot list is still a mood. The client sent three references and a sentence about "candid family stuff." Your assistant turned that into a generous paragraph. You still do not know whether the grandparents on the porch are a must or a hope, and the light will not wait for a clarification text at 4pm.
A shot list is a decision about time. Every added frame is a frame you will not make somewhere else. Write it that way.
Must, maybe, and what you drop first
Give them a closed must-have list they can read in one glance. Names, places, groupings. Then a short maybe list. Then what you will drop first if the day runs short, and why. That last line is the recommendation they can accept or reject without inventing a schedule.
Ask one thing: confirm the must-haves, or name the one swap. A decision shape is not "thoughts on the vibe." If they want to add a setup, they name what it replaces. An open "anything else?" is how a day grows after you have already priced the hours.
Do not attach the board and hope. RelayLink does not carry attachments. Describe the reference: whose picture, what must appear, what is only a feeling. Feelings belong in the note. Must-haves belong in the list.
Write for someone who was not in the planning call
The person who pays is not always the person who was on the call. Put the time, the place, and the hard constraints in words a cold reader can use. You assumed the baby will be awake at the hour you named. You assumed the second location is still available. You assumed uncle is in town. Label those. A correction on Wednesday is cheap. A missing person on Saturday is not.
Ask for a decision with a real date — when the list locks — and say what you will shoot if you do not hear. A default only works if you honour it.
You send it; they answer from the mail
You review the package. The note is in your voice, in names they use for their people. A nickname you keep in your contact list does not travel into the briefing. Do not write "the Millers" in the package if that is only your word for them.
They do not need an account. If they have never activated RelayLink, this is email and a link. If they already have an activated account, you need an accepted pair for a new thread. They can reply from the email. That reply is the list you both hold on the day.
If two people are hiring you, one briefing still lands in one mailbox. Say that the other person needs to see the must-haves. Do not treat silence from the second person as agreement.
After they confirm
Send back the locked list in the same shape, including the drop order. Ask them to correct a name or a grouping now. The day is for making the pictures, not for discovering who was supposed to be in the first frame.