Decide what to actually pack without over- or under-packing
Packing for every "just in case" is how a carry-on becomes a checked bag full of things you never wear.
- Use it for
- Anyone packing for a trip who tends to either overpack or forget something.
Packing lists default to either a generic template (which overpacks with items irrelevant to your specific trip) or an anxious "just in case" process that keeps adding low-probability items until the bag is full of things that never get used. Neither is actually reasoning about this specific trip's real activities, weather, and constraints — a good packing list is built from what you'll actually be doing, not a generic checklist plus anxiety.
This prompt builds the list from your actual itinerary and constraints, and specifically interrogates "just in case" items before they make the cut.
When not to use this
For a very short, simple trip where packing takes two minutes of common sense, this is more process than it's worth. This is for a trip complex or long enough that you've historically either overpacked or forgotten something.
Did this work?
Every item on the final list has a specific reason tied to the actual trip — no "just in case" items, and nothing obviously needed is missing.
Tested on claude-opus-5. Evidence status is draft; it moves to battle-tested only on recorded runs, never by hand.