Any of my SOSU trombone and euphonium majors will tell you that a signficant portion of their weekly lesson time is spent focusing on fundamentals. I consider this to be the pedagogical equivalent of "measure twice, cut once" described above. A typical lesson begins by playing some sort of melodic study, such as a Cimera or Bordogni. Through this music, we can discuss the proper use of air to create the necessary sustain and direction on long notes. The lesson may briefly divert into focusing on specific intervals, directional slurs or natural slurs if I can hear a pattern creeping into their playing. This is followed by Arban exercises or short, technique driven etudes from Hering, VanderCook, and other similar studies. By working on these contrasting styles, I can draw the distinction between legato slide technique (hold longer, move at the last possible second before the next note is articulated) and the slightly more relaxed, but just as careful slide technique used in technical playing. This approach is counter-intuitive, and must be seamlessly engrained into a trombonist's playing.
In my early undergraduate experience, my trombone playing suffered from a serious case of "cut first, ask questions later." This is a haphazard approach at best, and one I don't suggest adopting. The riskiness of this approach manifests immediately in shoddy performances, which should be reason enough to consider a more thoughtful and thorough approach. However, the more serious long term concern is the risk of compromised playing health. While I am certainly not an expert on these matters, I take my role as teacher very seriously, and wish to do no harm!
I don't mention these risks to scare anyone. In fact, I know many players who forego their daily routine and sound just fine...right now. But take a look at the best in the business, and across the board, you'll find that the players with the greatest command of their playing skills are the ones who know exactly where those skills measure up each and every day, and then apply those honed skills to their music in a deliberate, master craftsman sort of way. The fact that the oldest, most experienced master carpenters and woodworkers take more time to measure and make their cuts in a deliberate manner is proof positive that the longer I play trombone, the more I need to do the things that help maintain my playing abilities.
As always, I welcome your comments. Reply here, or drop me an email at brucefaske (at) me.com.