What are the top tips for mix roughness 3D models?

When mixing roughness in 3D models, focus on real-world reference, layer subtle variations, and test lighting interactions to avoid flat or unrealistic surfaces. Real-world reference matches how materials naturally behave—like smoother high points on a worn chair leg or dusty patches on metal. Layer small, gradual changes (e.g., fine scratches, light grime) to add depth without looking artificial. Test under different lighting (soft ambient, harsh direct) to ensure roughness reacts correctly, as light scatters differently on rough vs. smooth areas. For beginners, start with a simple object (e.g., a plastic bottle) and adjust one detail at a time—like making the cap slightly rougher from handling—to build confidence without overwhelm.