Watch the C m11 Tuning online guitar lesson by Vicki Genfan from Essentials: Open Tunings
Notice how quickly my fingers come off of the harmonic brushes. Getting the harmonics to really ring depends on two things: 1. The exact right location, holding your finger right on the fret and 2. The right touch - very light with a quick release. If these are new to you, please take your time and practice getting a great ringing sound before you try to play the etude.