Tio, I am no instructor, but as a student, I can say that learning basic versions of "Red Haired Boy" and "Billy in the Low Ground" (see here: http://www.bluegrassguitar.com/top10.php ) and playing along with a metronome and foot tapping has helped. They are to be played with strictly alternate picking, down on down beats, up on up beats. It helps, but I still need work though. That is more fun to me than alternate scales, though I suppose that would be good for me to do too so I learn my scales better.

To relate that suggestion to Robert's lesson, I like sometimes to add some vibrato or a little bend like Robert is doing above to my bluegrass fiddle tunes to blues 'em up a bit. Probably not approved by blue grass purists . . .