To fully immerse yourself in the retro diner experience, create a menu that reflects the era. Offer classic dishes like burgers, fries, milkshakes, and homemade pies. Use retro-inspired fonts and designs for the menu boards or printed menus. Consider adding fun names to the dishes, reminiscent of the 1950s or 1960s. This will add an extra touch of authenticity to your retro diner theme.