I use a triple dose dry powder inhaler every morning, I was told by the nurse if I have a lot of powder landing in my mouth I wasn’t sucking hard enough, or it was coating the back of my throat it was sucking too hard, I have to inhale the powder and then hold my breath for 30 seconds, not an easy task some mornings.
I was given a dummy inhaler to practice with, it would play a note when air passed through at the correct rate, it did help even if the wife got annoyed by the noise as I used it, not that I ever did it just to get on her nerves.