What's the most common mistake when building composites?

Pulling the wrong slot from an item — e.g. using item 1's action instead of item 2's — which scrambles the decode.

The discipline is strict: item 1 contributes only its Person, item 2 only its Action, item 3 only its Object. Slip-ups that corrupt recall:

• Using an item's own full PAO instead of just its assigned slot.
• Reordering slots (object first) so decode is ambiguous.
• Letting a vivid base image tempt you into the wrong slot.

Keep the mapping mechanical — first→Person, second→Action, third→Object — every single time.