Agree on the shared harmonic reference
Both guitarists should start with the same verified chord progression and section map. If one uses a capo, compare sounding chords rather than assuming matching shape names mean matching harmony. Play the opening progression slowly together and listen for accidental transposition or different change timing. Settle those basics before discussing tone or embellishment. Two individually plausible charts can still disagree about an extra measure, an inversion, or a final repetition, and those differences become much more obvious when the parts are combined.
Assign contrasting jobs
Let one guitar establish the main pulse with a restrained strum while the other uses sustained triads, a light picked figure, or short responses between vocal lines. Separate registers where practical. If both players strike full low chords at every opportunity, the result may become thick without becoming clearer. Decide who carries any important bass movement, especially in a duo without a bass instrument. The second part should fill a musical need rather than continuously demonstrate that a second guitarist is present.
Rehearse by subtraction
Play a verse with both parts, then repeat it with each guitar alone. Listen to what each contributes and where the combined attacks obscure the vocal. Remove or relocate overlapping fills before adding new ones. For a chorus, try a broader texture from only one player while the other maintains contrast. AudioChords can provide a common harmonic reference, but the arrangement emerges from listening to each other. Record a complete run and check entrances, stops, and the ending. A strong two-guitar part often depends on one musician leaving a space that the other knows how to use.