I think bending and vibrato are the most telling sign if a musician is good or great. How many times have you heard a guitar player in a cover band play a solo note for note, but it lacked emotion and feel? Chances are that player learned all the licks but never played it along with the CD.
One of the best ways to develop your vibrato is to listen to singers and horn players. They have a natural vibrato because they have to breath, while guitar players can noodle forever. Try singing the solo aloud or in your head while playing it and it will become a lot more natural. I think you really need to listen to what is coming out of the speaker and detach yourself from it.
If you think about guitar players with great vibrato, Jeff Beck, Steve Vai, Eric Clapton, Stevie Ray Vaughan, Eddie Van Halen and Carlos Santana, they each have an individual style and their vibrato is very recognizable. I'm sure all of those guys spent a lot of time
developing it. I know players that have a lot of technique, know their theory and so on but have never spent time developing their vibrato, and you can tell right away.
To start working on vibrato try developing a swing ala B.B. King with all four fingers and see how long you can make a note sustain by gently rolling your hand from side to side. After that becomes smooth, start bending strings. First play a note that you want
to bend to then move down one fret and bend to that note (a tuner with a built in mic can really help). When you are comfortable with a one fret bend do a two fret bend and a three or even a four. Make sure to nail the pitch.
Take a solo that you already know and listen to every bend. Play along with it and match it. You cannot look at a squiggly line on paper and have any idea what it should sound like. Vibrato is one thing that defies notation and has to come from inside you. I hope this helps, now go make some noise!
Mike O'Malley's instrumental power trio is called No Walls and their latest CD is entitled "World Abroad". He has been playing guitar for almost 30 years and graduated from Music Tech in Minneapolis in 1988.
O'Malley currently has 45 guitar students that range in all ability levels and styles.