Watch the Finding Melodies with Triads online guitar lesson by Matthieu Brandt from Songwriting on Guitar
One downside of using the guitar as a songwriting tool is the influence the chord shapes have on our abillity to hear melodies. The top notes of the chords we play will often guide your ear towards a melody. This can be confining at some point, because these are by far not the only melodies that are possible. Experimentig with triads of the chords in your progression can give you more insight in what melodies you could use. Finding these triads on the middle or top three strings and analyzing which roads you can take, going from one chord to the other, will expand your melodic options.