better still,
instead of using a capo,create inversions,by learning them ,that requires making a diagram of your finger board,learning the notes of the chords,and hey presto ,you can see all your different inversions.
in standard tuning,there are quite a few options ,for most chords.
next step,is have one guitar in a different tuning drop d, double drop d,or open d dadf#ad,or open G gdgdgbd.
or even consider a modal tuning dadgad or cgcgcd,probably the easiest to start with might be dgdgbd[originally a blues tuning] sees harleys website.
this depends to some extent on what keys the singer likes to sing in.OPEN G IS OF COURSE GOOD FOR G,but using acapo you can play in any key,while the other guitar is in standard,or drop d playing in g.