I've been working on mastering the train chug sound and keep stumbling over myself when I speed it up. Is it faster to do a "chug chug" type approach or something similar to "ooota" (draw) "hoota" (blow)? I am using my diagphram to push the air in and out quickly. And is it necessary to do a wha wha handcupping effect at the same time? If I do master this, I'll be holding a Green Bullet when I do this live.
I've read about Joe Filisko's Train Exercise #1 and the James Cotton Mississippi Freight Train techniques and have been trying both.