The way you develop a monologue should be based on the
desired outcome of that preparation in an actual audition. In other words, how
do you want it to play for the casting director?
The usual approach is to lock down the line readings in an
effort to get a uniform level of performance in each audition. This seems like
a reasonable strategy but by locking in line readings, emotional levels, etc.,
you are actually insuring that your monologue will seem canned and that you are
unresponsive to your audience. At best, the casting director will see your
performance as a clever reading of the material. At worst, they will focus
judgmentally on the line readings you've chosen, and in doing so, completely
miss your “acting”.
If you shouldn't lock down the line readings, then what
should you do? My suggestion is that you explore the lines by “talking” them.
This is best done with a rehearsal partner and an awareness of what actually
allows you to talk your way through the words of your monologue.
Next… The Amazing Mouth Machine.