Questions to consider responding to:
What questions are you left with? What other topics, issues, or readings did this reading make you think of? Does it challenge, or is it challenged by, arguments and evidence posed by other authors? Were there parts of the text you found troubling, complicated, or fascinating that you would like to discuss in some detail?
For ethnographies, try to focus on the methodological implications of the text, such as: What evidence do they use to make their arguments? What questions do you have about their method (what they did, who they talked to, what they talked about, etc.)?
For texts on method: Do you have questions about how to put a particular methodology into practice, or questions about how this might relate to your own research?