When getting permission, explain the purpose of the review and how the results will be used. A great method is to have someone else lead the session, while the author sits there, taking notes but not talking. At the end, the reader and the author can talk freely. Greet the reader, who has just arrived. Use the magic incantations to lull the reader into the right mood, avoiding words of judgment or even discussion.
Humans can really only do one thing at a time.
After only about five minutes of awkwardness, if you've set the mood correctly, most readers will relax into the process and be almost completely natural. Remembering to be tense, when they're engrossed in your work, usually proves to be too much mental overhead. They sound cumbersome but after only a few links you and the reader will get into a rhythm and together discover some astounding stuff. Don't twitch or gasp no matter what happens . Also try to keep the author from twitching or interrupting.