Before the 1st rehearsal,
- Talk to the soloist.
- Cut any unnecessary orchestral tuttis or introductions. (Perhaps the introduction was intended for a performance of the entire opera and you are performing just one aria.)
- Determine all tempos.
- Schedule rehearsals.
- Simplify your part if necessary.
- Play fewer notes well. Do not perform poorly because you attempted to play all of the notes.
- Eliminate unnecessary octaves, thirds and doublings.
- Augment (slow) tremolos and other fast passages.
- White out difficult notes or rewrite troublesome sections.
- Finger your part.
- Find your solo lines.
- Determine page turns.
- Learn your part.
- Learn the other part(s).