It’s better to be sharp than out of tune.
You always have time for the things that are important to you.
Never speak ill of another player; such talk always boomerangs eventually.
For unreasonable conductor requests (e.g. continual demands to play softer), after you reach your limit play exactly the same thing and keep asking “How was it this time?”
Transposition “mental key signature” rule of thumb: – if it’s a sharp key, add a sharp; if it’s a flat key, add a flat. E.g. Horn in G: one sharp for G major, add a sharp = 2 sharps, or D major; Horn in Eb: three flats for Eb, subtract a flat = 2 flats = Bb major).