Watch the Wide Vibrato online guitar lesson by Chris Buono from 60 Electric Guitar Techniques You MUST Know
Vibrato on steroids is one way to describe what a wide vibrato technique sounds like. Often associated with hard rock or metal, wide vibrato delivers intensity and energy to any riff or lick idea. It's total rock star stuff. Simply applying more movement in your finger vibrato technique is a good way to start. Even better, watch your favorite wide vibrato wizard in action and study their every move.
Looking for inspiration? Zakk Wylde is a good place to start, as is John Sykes most notably for his stellar playing on the self-titled breakthrough Whitesnake record released in 1987.