Here are a couple of suggestions:
Not really questions, but have you ever used the “I Can” bookmarks with your kiddos? Sometimes just introducing something new can “ooomph” up our conferencing. There are “I Can” bookmarks for many strategies, and they can be used as reminders during Read to Self time, as well.
https://www.thedailycafe.com/cafe/resources/i-can-bookmarks
One area I often try to remind myself of is to keep conferences short. Sometimes we (I) get ourselves a bit too involved in what we’re doing rather than concentrating on what the child is saying–does that make sense? The link below links to a document to remind us of how to keep in mind when conferring. http://www.thedailycafe.com/sites/default/files/legacy_files/Conferring_how_to1%5B1%5D.pdf
Just somethings to think about . . .

Here are a few that come to mind that really get the student doing more of the talking during the conference:

• What did you notice about your reading today?
• What strategies worked for you today?
• Can you tell me why you chose this book?
• Tell me about how (insert strategy here) is going for you…
• Do you have any questions for me about your reading?

Also I LOVE looking over the running records with the students and having a conversation about what information this gives us about their reading.