I have done this two ways:
1. I give one large (2 minute or so) comment about the whole paper at once.
2. I give smaller comments throughout the paper highlighting specific things.
I prefer way #1 but #2 also works well.
You may be wondering why I do this or what benefits I have seen, so let me elaborate.
When I give verbal feedback the students have told me it feels less harsh than seeing a paper with red, green, or purple marks all over it. They say they can tell by the tone of my voice that I am not upset or disappointed but that I am truly trying to get them to improve their techniques.
I like doing it because it helps me focus on the big picture items. Is their paper organized, are they on topic, did they use evidence appropriately instead of spending 10 minutes finding every single spelling and grammar error in the first two paragraphs. I don't ignore those errors but I will say something like "there are several spelling errors in your first paragraph, please review" or "The second sentence is a comma splice. Review your notes and check your paper for others and fix them." I believe that this puts the responsibility on the student to fix their mistakes. (I do most of this on the first draft.)
I also like that it saves me a lot of time. Like, a whole lot. I have found I can read a 5 page paper and leave initial feedback in about 5 minutes total. It takes slightly longer if I'm reviewing a final draft, but I've changed my method for that as well because I am now using the portfolio method which I'll discuss in a future post.
If you don't use google drive you can use screencastomatic to record videos of you commenting on their paper using screencast software and then email them a link to the video or a copy of the video.
I know a professor who has students record comments back to him which creates a type of conversation between them! The options are plentiful.
How do you grade smarter?