Cultivating a Bad Sound

You're cultivating a bad sound.

That is what my tuba professor at Northwestern, Rex Martin, used to say whenever I would play any note without using my absolute best sound possible.  That included quickly touching a note to get a pitch in my ear before buzzing.  It also included ghosting a note down an octave before playing a note in the high register.  He made me apply the concept to every single time I ever played anything and it is some of the best advice I've ever received in my career.

Every time you play anything you are reinforcing something.