For example, play C major triad instead of A minor 7th. (Nobody will notice!)
Banjo-playing friends have since reminded me of two more similar tricks. One friend said 'Because we have four strings, we often play partial chords, as the full chord pattern on each inversion would stretch fingers beyond human limits at times'.
The music calls for a Diminished Chord. Instead, play the 7th of the chord one semitone below it. But LEAVE OUT THE BOTTOM NOTE. For example, for F diminished, play E7th (but leaving out the E at the bottom). It works.