My low C#'s are way sharp. I've been told to use the kick valve (left hand valve in the front) to flatten the tone. Works like a champ, BUT when exactly do you "kick" it out? On long tones only? Kicking it out seems kinda clunky with that finger, so it seems like you can never get it to be very efficient, like kicking it out on quick runs, etc. Thoughts? I just want to know what to practice...kicking it out every single time I play a C#, or only certain times. TIA!