Watch the Major Triads online guitar lesson by John Stowell from Modern Jazz Improv
The four major triads here generate inside embellishments (6, 9, 11, #11) and can be used any time a major chord appears in a progression. Notice that I'm also using the major triads as substitutions for the major chord as well, in some cases creating progressions of triads. You can practice triads in pairs outlining inside sounds (C and G major triads/C major), chromatic movement (E and F major triads/C major), or outside harmony(E and C# major triads/C major). The number of bars/beats you have to work with in a tune and the musicians that you're playing with will help you shape your harmonic choices.