Asked directly through hangouts, so it does not clutter their email. They can answer it whenever they see the question. I use the same general format for all requests for feedback:

"Good morning/afternoon, If you don't mind giving me some feedback, I would appreciate it. You do not need to respond immediately. You may respond right in this chat. (Insert the feedback question and clarifications). I appreciate any feedback you are comfortable giving me."

After they provide the information, I record it in a spreadsheet, to keep track of which students I have/have not asked feedback. Identify trends or patterns in the feedback before taking action or making changes. Then respond to them with at least: "Thank you for sharing that information with me, I really appreciate it."

If there is any feedback that I need more information about, I ask follow-through questions. These are voluntary because I do not want students to feel put on the spot or worried their comments will influence my attitude toward them

Yellow cells indicate students who have not yet responded, but they may at any point when they see the message in Hangouts. Red text indicated possible areas for improvement and follow-through questions. Each week, about 25% of my students are sampled for feedback. The sample is different from week-to-week, ensuring that all students have the opportunity to provide feedback that will influence their experience in my classroom.

Using the spreadsheet allows for me to track and build upon the feedback over time. It also provides me a record of which students have been contacted, so that there is equity in opportunity.