I just went to see Wynton Marsalis and he said in order to have a clear tone you must hold long tones very soft and hold them as even as you can without any bumps. you should start on the second line g and go down chromatially each note should be for a minute long

I`ve been playing my horn for almost three years and i just love hitting those high notes... I think that it`s true that if you do long tones and just keep your lips relaxed for a long time it will help out a lot. I also think that if you want to hit every note clean and perfect you should practice on attacks.

if you push more air through it willhelp