You can preview rule of three designs before buying furniture by using digital tools or apps that allow photo uploads of your space. For example, upload a living room image and experiment with a 60-30-10 color palette, then add three pendant lights or three framed prints over the sofa virtually. Adjust spacing, heights, and finishes until the group's balance clicks. Saving these designs creates a personalized shopping roadmap, ensuring you buy furniture and decor pieces that harmonize and follow the rule of three effortlessly.