Indie Birth website has a blog post answering your question also! Check em out :)
Talk out different scenarios and see how they would handle them. Are they a midwife more naturally minded or what I like to call a medwife which is more medically minded. I thought I had a midwife and ended up with a medwife. I was pushing 42 weeks so she wanted me to deliver in a hospital which was TOTALLY against what I wanted. I ended up having a beautiful home birth but she did a lot more medical things than I had thought would happen.
I find it helpful to ask what their philosophy of birth is and under what circumstances they would transfer you to a hospital and what care in those circumstances would look like. Also asking if you can choose the position you’d like to give birth in.