By layering the warm-up conversation and watching their energy. The conversation hot button is the topic that changes how they talk — faster, warmer, more detailed — and you find it by keeping the talk about them, following the threads that carry energy, and asking for their advice, which invites people to teach you what they care about.
The short answer
The warm-up layers exactly like discovery does: ask, listen, follow the answer one level deeper. Small talk stays small when you hop from topic to topic; it opens up when a follow-up tells them you actually heard the first answer. Keep the subject matter on their side of the fence — the home, how long they've been in it, what they've done to it, the neighborhood, the family that fills it.
Asking for their advice is the documented accelerant. People who will not perform enthusiasm for a stranger will happily instruct one: how long the winters take off the back rooms, what the last contractor did wrong, what they'd do differently with the yard. Advice-giving reveals priorities — and priorities are what hot buttons are made of.
How it runs
Find the conversation hot button and you have a preview of the buying hot button you will hunt in discovery. The topic that animates them over coffee is usually connected to the problem that will move the decision — the room that's always cold, the roof they worry about every storm, the house they want to be proud of again. Note the exact words they use for it. You will use those words back in the presentation, where they carry ten times the weight of yours.
Spar trains the documented sequence, step by step, and grades what you actually ran. Round 1 is free. Spar before you knock.