I like to have yetis as a reclusive near-human race that has adapted to "hive" living in the resource-poor mountains and high plateaus. Fluffed somewhat after the stereotype of Tibetan Buddhism, they live in small monastic temple-colonies, tending to terraced fields and herding yaks under the direction of a priest caste.
Depending on their upbringing, they will develop into one of several castes: warriors, laborers, and priests. Warriors are tall, broad, with bodies covered largely in thick hair, and possess a pair of large swept-back horns. As the "standard" undifferentiated caste, laborers are most similar to other humans, though somewhat broader and more hirsute. Priests/priestesses are frailer, with four short straight horns, and more distinct body hair pattern - concentrated on their shoulders, forearms, and crus. Warriors are uncommon and fulfill both military and heavy labor roles, laborers are essentially the common population, and the rarer priests fulfill the administrative and ceremonial needs of the temple-colony. In truth the caste system is more of a gradient, and it is not uncommon to see such sights as a warrior-like "laborer" tending to a herd.
Most Yeti (or "Himamanav" in this setting) have stark white hair and olive skin, though black hair and paler or darker skin is not uncommon. Irises are uniformly amber, with the rare exception of muddy-red in priests or green in individuals with Human ancestry. All have two sets of upper canine teeth, a predilection for dairy and meat, and an intolerance of alcohol.
Culture varies between temple-colonies, but there is usually a strong value placed on spiritual correctness and communal sufficiency.
Despite superficial similarities, they do not appear to be more related to the primitive Woses and Sasquatch of the temperate forests than Humans are.
>pic related could represent a particularly robust warrior, sans horns - most would look more clearly human, but this is within the range of variation