Start with your ethnography. Get to know the culture you have chosen and the objects important to that culture. If you do not know what people you would like to study browse the ethnography pages for ideas.
Once you know more about the culture you have chosen visit the visual guides for ideas. These are kept at Pinterest and you will either need an account or sign in with a Facebook account to view them but they include images of objects from museums and blogs around the world. While many of these objects would be very difficult to duplicate they might still give you ideas of materials or types of objects to investigate.