The best way to scale a faces 3D model is to use 3D software for proportional adjustment, locking all axes to preserve facial feature ratios and avoid distortion.
Proportional scaling keeps eyes, nose, and jawline balanced—critical for realistic or stylized results. Tools like Blender’s "Scale" tool (with axis lock) or ZBrush’s "Transform" palette let you adjust size while retaining original proportions.
This method works for game character design (matching concept art) or 3D printing (fitting print beds).
If you’re new, scale incrementally and cross-check with front/side reference images to keep features natural.