In this lesson video, which hit the interwebs almost three years ago, Rick Graham—a UK-based guitar instructor with 100,000 followers on YouTube—shares the five simple steps that he feels truly helped him improve his (very impressive) legato technique.
His steps, all of which are explained in detail during the video, is something of a checklist featuring:
1. Thumb and left-hand positioning
2. Muting technique
3. Controlling tension
5. Building speed.
"Just to clarify, my legato technique consists of hammers when ascending and pull-offs when descending, even when using [my] left hand only," Graham says.
By the way, if Graham looks familar, it might be because he was featured in a recent Tyler Larson video, When Your Online Guitar Students Should Be Teaching You. You guessed it; Graham is the guitar student who should be teaching teachers.
For more (including much more recent) videos by Graham, follow him on YouTube.