Nike Air Force 1s are made with high-quality leather, suede, and other premium materials. Fake shoes often use cheaper materials that are noticeable upon close inspection:
Leather quality: The leather on authentic Air Force 1s is smooth, soft, and durable. Fake leather may feel stiff, plastic-like, or even overly shiny.
Suede: If the Air Force 1 has suede elements, the texture should be soft and velvety. Fake suede may appear rough, uneven, or lack the subtle nap of real suede.
Smell: Authentic Nike shoes have a specific, non-chemical smell. Fake shoes, especially those made from synthetic materials, may have a strong, unpleasant odor.