[Trombone-l] Galen's bass trombone doubling question

[Jackie Harris-Stone]

I started out using a rough copy of my rim on a Doug Elliot mouthpiece.  That worked pretty well- he suggested a lucite rim.  (I was a longtime member of Tom's trombone choir, and saw how well it worked for him!)
 
However, I'm giving my son playtime on the alto trombone, so am using my 12C to play for him most days while he moves the slide, not wanting to risk any instrument or mouthpiece I commonly play on to the self-control of a 17 month old.  (He loves taking the mouthpiece in and out of the case, and hasn't thrown it on the floor yet, but I'm not taking chances.) I normally play bass trombone with some tenor doubling, so this is a big mouthpiece switch.
 
I find that the two things that help me double are:
 
A.  Good use of air.  Until I got accustomed to switching, I practiced with air only for the first part of any horn switch, even if just a quick warmup
B.  Switching became really easy when I started free buzzing, and matching pitch- the goal being to remove my horn from my face at any point while continuing to buzz, and have the note I was buzzing match that which I was playing.  (An intermediate step is to match the pitch you buzz your mouthpiece to that you free buzz, and match the pitch you play your trombone to that of your mouthpiece.  Don't cheat and change the pitch as you're switching from one setting to the next!) 
  Once the mouthpiece stopped being a crutch to get the notes, and the horn became merely an extension and focuser of the buzz, it didn't seem to matter which mouthpiece/horn I was playing.
 
BTW, I wonder if you did this if you would find that you had to go through less contortions with the valve notes.