Assigning a fixed Person, Action, and Object to every item in your set — all 52 cards (or all 100 numbers 00–99).

* The 'build it once' end state — one fixed image locked to every item. — Pedros.lol, CC BY-SA 4.0, via Wikimedia Commons. *

It's a one-time construction job: go through each card (or number), and lock in three attributes for it — who it is, what they do, what they hold/use. When you're done you have a complete table (52 or 100 rows, three columns) that never changes. The upfront effort is real, but once drilled it powers fast encoding forever. Build it once, drill it hard, then use it for life.

Go deeper:

• Mnemonic peg system (Wikipedia) — situates PAO as the most advanced peg system.

Pick vivid, instantly-recognisable, clearly-distinct characters — celebrities, fictional characters, or people you know.

The Person is the anchor of each image, so it must fire instantly. Good sources: famous actors, athletes, historical figures, cartoon characters, family and friends. Requirements:

• Distinct — no two people so similar you'd confuse them.
• Vivid — someone you can see clearly, with a strong "look".
• Evocative to you — your associations, not a stranger's.

A roster of unmistakable characters makes every composite easy to picture and to decode.

Go deeper:

• Nelson Dellis — How to create a 2-digit PAO system — a champion walking through picking vivid, distinct people.