What to gather feedback on? I'm doing small group tutoring for an undergraduate course next semester and I'd like to gather feedback from students to improve my skills.

What are some questions I should ask the students in order to get useful feedback?

I want to do this with a quick (anonymous) Google form at the end of each session, but I'm open to other ideas about how to collect data.
Take everything with a grain of salt - if they like you they'll tend to be kind in their evaluations. It's also really easy to have anonymous surveys that yield ridiculously positive results (see the "analytics" used by just about any after school, drop in, or summer CS program for examples - using questions like "are you more or less likely to take another CS course").

Whenever I do an anonymous eval I do a few things:


Figure out a way to make it anonymous but to also make sure everyone submits one. Once I wrote a system that they could audit that collected responses and emails then scrambled the answers and sent it to me with a list of who responded separately another time I had the students send the results to a trusted third party.
Ask the kids for the good and the bad. I tell them that even the worst teacher does some good and even the best does some things wrong. I tell them that it's also nice to see some positive and if I only asked and got the negative it would be just to depressing :-)
The bad is important so I know what to change but the good is also important so I know what to keep.
I tell the kids that saying something is bad is ok. Better is why it's bad but even better is a suggestion as to how to change it.
If possible you want to follow up with the kids a semester or year later (if not longer). The perspective of time can really change opinions.