Watch the Various Chicks - Mid Strings online guitar lesson by Matthieu Brandt from Guitar Lab: Triads and Hendrixian Double Stops
In this lesson we'll continue to extend the three major triads and add colors. We'll keep the shapes as close as possible to each other to create smooth arrangements.
All the shapes used in these examples are moveable, because they don't contain any open strings. Switching to other keys becomes easy within this system of triads.
Special attention needs to be given to scale degree four and scale degree seven. Depending on the function of the triad you want to extend, you'll add a sus4 or augmented fourth and a flatted seventh or major seventh to the triad. Key is to keep using your ears.