My warm-up in the morning consists of about 6 mins of breathing, 2 mins of buzzing w/o mouthpiece, 5 mins of buzzing on the mouthpiece, then I do the suggested warm-up out of the Vizutti books. The Vizutti warm-up includes long tones starting on either C7, C-7, or Cdim7(b5), and then it goes on to some scale studies. I start the long tones at pp, and on some mornings I have a hard time with that attack. In fact, each time I come back to the horn during the day my response is lacking. I think that it's part physical and most mental. Anyone had any problems with this during your day, and have you come across any advice on how to approach this?