Look at common DIY escape room ideas for inspiration. Good 70s puzzles include using a Fortune Teller/Cootie Catcher to reveal numbers or using "secret agent" ciphers inspired by the Cuban Crisis or MI6 themes.
Use "groovy" fonts like Cooper Black or Bauhaus 93 . Incorporate colors like avocado green, harvest gold, and burnt orange to match the Escape from the 70's aesthetic . Physical Props (Paper-Only): Escape.from.the.70s.rar
Provide a colored transparency sheet (e.g., red or orange). When placed over a "static" or "jumbled" image on paper, it reveals hidden text. Step-by-Step Design Guide Look at common DIY escape room ideas for inspiration