So, what are these so called "professional secrets"?? Well, what unites most players that have a reputation for excellence in vibrato (such as Gilmour) it is the "vocal" quality of their vibrato that is most prominent. Just as with a singer you do not want them to use 100% vibrato on every note, or they would sound like Jim Carrey in the Cable Guy movie! However, to sing a pitch, and then gradually building into a vibrato, is the most common way of doing it.
This can also be done on guitar, allowing the note time to breathe, and establish itself, and then moving into your vibrato. Especially over slower tunes, this will be an excellent way to create felling and appealing phrases in your laying! Check out the examples below to see what I mean, and the video of course!! I'm elaborating on this topic in the video, so rather watch that then reading through me trying to explain this rather abstract thing.
One last thing of importance ot mention, is that variation is the key to any good vibrato. I think noone likes to hear a singer use the type of vibrato on every note in every song, and the same holds true for guitarists.
With that said, I'll leave you for now, and see you soon in my next tutorial!