From my experience its just a matter of practicing them. Do lots of "compound slurs" (jumping around through multiple partials. i.e. low Bb - middle Bb - F - D kind of thing)
I'm a tuba player so I'm talking concert pitch but the same principle applies.
I've been in the same position as you, the only way to get better is to practice your face off.
Hi I'm Ryan. I'm fairly new to DCP and want to introduce myself.
I'll be marching the 2013 season with the Santa Clara Vanguard Cadets, being my first year in drum corps.
TUBA
Completely Uneducated guess. Just throwing out what I'd like to see. Lets see how close i can get.
1) Carolina Crown
2) SCV
3) BD
4) Cadets
5) Phantom Regiment
6) Bluecoats
7) Scouts
8) Cavies
9) Boston Crusaders
10) Spirit of Atlanta
11) Crossmen
12)Blue Stars
13) Blue Knights
14) Academy
15) Colts
16) Troopers
17) Pacific Crest
18) Oregan Crusaders
19) Jersey Surf
20) Mandarins
21) SCVC