At a recent Forum Chat there was a discussion about finding that balance of supportive and motivational feedback to give to writers who have submitted their work to a group. I used to run a writers' group in Bath and we settled on this model and they still use it today. It is positive and supportive , also, it gives advice to the writer on how to prepare and deal with feedback. Here's a link to what I think is the best description of it.
I'd be interested to hear about any other structures people use, especially one that might work in a video-conference setting.