I usually start my practice sessions with a warm up, then practicing my octaves until I get up beyond my range ... then shift to practicing my pedals, which are pretty much below my range. So I start off every practice with some handy touches of failure.

Now. If I want to practice sounding beautiful, I must ask myself if I want to begin my practice sessions by pushing myself to failure.

Tonight I will wait until later in my practice to work on my high and low ranges, and really focus on playing with good sound first.