Eating customs vary throughout Kenya. Kenyans use the right hand or both hands to pass and accept items the left hand alone is improper. Traditional food is often eaten with the right hand while a knife and fork are often used with European cuisine. Pointing at someone with the index finger of either hand is unacceptable, as is touching an older person. Approval may be shown with both thumbs pointing up, while displeasure can be indicated by a ts-ts sound.
Eye contact is important in establishing trustworthiness.
The taking of photographs can be an especially sensitive subject in Kenya, which has over the years been the subject of numerous documentaries, photo shoots, tourist safaris, and more. While Kenyans often bear this scrutiny with good humor, it is considered rude to take a photo of someone without asking first. Many times, people will happily grant you permission. Many times, they'll also ask for money. If you really want that photo, pay up.