Three turns and a check. Keep this open next to your chat: each step is the thing to paste next, with what you typed already carried across. Nothing is sent from here, and nothing on this page is a transcript. The conversation stays where you are having it.
Every unresolved point, with both sides' current positions.
Size, structure, timing, and the consequence of no deal for your side.
Your side and who on your side actually decides.
Who they are and how they have negotiated so far.
The law that changes what a position is actually worth.
Watch for, the whole way through
A plan built on inferences about the other side's priorities is only as good as the inferences. Test each one in the first twenty minutes rather than defending it for three sessions.
The model has no deal data and will produce market claims that sound authoritative and are invented. Do not carry any of them into a room.
Negotiation plans are work product and they describe your walk-away. Keep them out of anything that travels to the client's shared drive or a deal site.
A walk-away your own client has not approved will be abandoned in front of the other side, and the abandonment costs more than never having stated it.
Whether a term is enforceable at all changes what it is worth to trade. Confirm the governing law question before spending leverage on a clause that may not hold.