One of those web things I found years ago and don’t know the origin of:
Golden Rules for Ensemble Playing
1. Everyone should play the same piece.
2. Stop at every repeat sign and discuss in detail whether to take the repeat or not. The audience will love this a lot!
3. If you play a wrong note, give a nasty look to one of your partners.
4. Keep your fingering chart handy. You can always catch up with the others.
5. Carefully tune your instrument before playing. That way you can play out of tune all night with a clear conscience.
6. Take your time turning pages.
7. The right note at the wrong time is a wrong note (and vice-versa).
8. If everyone gets lost except you, follow those who get lost.
9. Strive to get the maximum NPS (note per second). That way you gain the admiration of the incompetent.
10. Markings for slurs, dynamics and ornaments should not be observed. They are only there to embellish the score.
11. If a passage is difficult, slow down. If it is easy, speed it up. Everything will work itself out in the end.
12. If you are completely lost, stop everyone and say, “I think we should tune”.
13. Happy are those who have perfect pitch, for the kingdom of music is theirs.
14. If the ensemble has to stop because of you, explain in detail why you got lost. Everyone will be very interested.
15. A true interpretation is realized when there remains not one note of the original.
16. When everyone else has finished playing, you should not play any notes you have left.
17. A wrong note played timidly is a wrong note. A wrong note played with authority is an interpretation.