Reinhold Friedrichs background for warming up was mostly based on James Stamp, but he developed and changed things.
1. "Glissando" on the mouthpiece.
Hold the mouthpiece light (see picture).
Start with a G in the staff.
Slide down a fifth and up again, then continue up to a fifth above
and return to starting note (G).
Then start on F# and do the same
Then start on F
Continue down to low C.
A shorter version is to go an octave down and up.
2. "C major with F#" on the mouthpiece.
This is based on a Stamp pattern but on a C scale with F sharp instead of F.
Start on C (like in the picture above).
Then start from D (up to A, down to D, up to E and down to D).
Then from E,
as high as comfortable.
Play it with a "flowing feeling", not so
strickt. Let the air flow.