Something to Play
In my experience, most guitarists like to have something nice to play on the guitar. And then, the option of a musically similar yet different variation.
This is easier said than done, depending on the the style and musical range of the guitarist.
"Learning Modules" on this website offer two approaches to developing this sense of casual musicality. Firstly, each module has a moderately simple 4 bar chord chart. Many guitarists will actually find the chord structures slightly unfamiliar. If they like the sound, then to find something similar to play, another learning module from the same key signature is going to be a sensible place to begin.
There is also another approach, and that is using a variety of musical resources found within a single learning module, to imagine a new progression to complement the project's chart. This range of content is in production, bringing "melody arpeggios" and "enharmonic intervals" for the interested guitarist's enjoyment.