Everything the tools compute, explained as things you can do yourself — with a tape, a mirror and daylight.
How to Measure Your Face Shape at Home — A ruler-and-mirror method that matches what face-classification apps measure: four distances, one ratio, three width comparisons.
The Three Zones and Five Eyes, Explained — The classical Chinese proportion framework — what 三庭五眼 measures, what it does and does not claim, and how to eyeball it on your own face.
Photo Lighting Basics for Face Analysis — Why your bathroom selfie confuses every face tool — and the three-light setup that fixes it, with nothing but daylight.
Take a Compliant Passport Photo at Home — The rules that get home-taken ID photos accepted — background, head height, lighting, and the three mistakes that trigger rejections.