To complete the retro diner theme, incorporate accessories that evoke the nostalgia of the era. Hang vintage posters or framed advertisements on the walls. Display retro-inspired kitchen appliances, such as a jukebox, milkshake maker, or vintage coffee machine. Use retro-style tableware, including chrome-trimmed dishes, glassware, and napkin holders. These small details will enhance the overall retro vibe.
