Watch the Two-Hand Tapping online guitar lesson by Chris Buono from 60 Electric Guitar Techniques You MUST Know
Two-hand tapping AKA Emmett Chapman technique involves both hands tapping single notes (less often) or chordal (more often) instances. Even if you're experienced tapper of one or more approaches, two-hand tapping is a whole new world. Keep in mind your pick hand will need time to develop compared to your fret hand, which by default has had a massive head start on fretting notes.
Looking for inspiration? Right from the get-go, the de facto heavyweight champ is Stanley Jordan. However, with the proliferation of the tapping culture, more and more players are coming out with incredible two-hand tapping techniques such as Tosin Abasi, Yvette Young, and the incredible glitch tapping technique from Josh Martin of Little Tybee.