When playing a chromatic scale from low C to the octave fast my fingering is not clean when I go from the 2nd and 3rd valve to any other valve or valves. I know it's primarily something that should be practiced over and over again with a metronome. But I'm wonder if there are any other bits of information anyone can offer to help me? Arturo Sandoval emphasizes "slamming the valves down". I've taken his meaning with a grain of salt and applied his intention without the success I'm looking for. I don't have a teacher for personal reasons, and hope to pick up some advice on TM. I hope it's not a matter of a mental block that I've created?