GET A USEFUL FIRST RESULT

Play one round before building ten.

Give the assistant the group size, available time, and any knowledge everyone can fairly be expected to share. Ask for the rules, a worked round, and a separate answer key. Test the smallest version before producing a whole evening of material.

Solve every puzzle yourself and look for ambiguous answers or clues that depend on private knowledge. Offer alternatives when a physical task or reference will exclude someone.