Here's page one of a chart for a film. Now while it says "Gtr Part" it was really intended to be played down an octave and on baritone electric. I used my Danelectro for the job.
A couple issues.
One, I don't read for baritone very often. So I was kind of double transposing twice to play this chart. Down an octave and then up a fourth. Not really up a fourth, but for example that first note, D, is really the D an octave below that and on the baritone it is played on the 3rd fret of the sixth string. So kind of like a G note on a normal guitar.
There was a lot of baritone on this score so I was quickly able to get my head into the bari-game. Generally I think of that first note not as G but as D right where it is. Just as it is. And then I just read the intervals instead of the notes. So D, then two more D's, up a minor 3rd, up a whole step. Hit that again. This trick will get me through many tricky transposition situations.
The second issue was with the length of the neck. My left arm was getting tired. I don't know how bass players do it. I have no tip for this except play more baritone.
Here's a video on the subject...