Several years ago, I was fortunate to see Trevino do a clinic at D A Weibring's former driving range that was located at the Tollway and Spring Creek in Plano, Texas. To say it was an amazing display of ball striking would be an understatement. As other posters have said, he could hit any shot he wanted on command, all of which were dead solid.
D A was there and was sort of the straight man - asking Trevino questions, requesting he hit certain shots, etc. Weibring asked him to talk about a nine hole match he recently played in Fort Worth where he used just one club and the other guy had his full set. Trevino said he used a high lofted fairway wood as his one club. Weibring asked him how he managed to do that. Trevino proceeded to hit a series of shots to various targets with the club - from 100 yard high shots to about 220 yard drives - all by opening and closing down the club face and changing the length of his swing to hit the shot he wanted. It was incredible to see him change the trajectory and hit shots to the correct distances with that one club.
He's quite the showman. You could tell he was loving every minute of it, and so was the audience.