During the webinar "Prove It! Testimonials That Sell" Jeffrey Gitomer and Andy Horner laid out a sequence of 7.5 questions you can ask your customer to get a top-notch testimonials. These questions work exceptionally well for video testimonials.
Sit down with your customer, hit 'Record,' and ask these 7.5 questions to get to the "wallet" of the testimonial. Watch the video to see what I mean.
You can also watch the entire webinar for free on Udemy.