I need to try those spreads
I also love giving readings at Halloween, and when at a party I'd recommend going for a shorter spread, like the aforementioned P-P-F.
The one I used last year was Trick or Treat.
Costume: What you're wearing for the party - the situation.
Trick: The shadow/the unexpected
Treat: The positive side/opportunities
The Candy Bag: What you can take home - the outcome.