I'm an ACMI guy who stuck his head in here looking for another thread but figured I might share a few secrets for how I pack into a 19" carry on for 20 day trips (weeks worth of clothes before laundry).
Clamshell aluminum bag (reccomend Zero Hallburton).
Use "passenger size" toiletries.
Dedicated and compact toiletry bag.
Shoe travel bag.
These should all fit squarely into the top clamshell.
2 uniforms. Pressed and flat.
3 white t shirts. 4 other t shirts. 7 boxers. Rolled.
2 shorts pressed and flat.
Load squarely into the larger clamshell.
This is enough to get the job done and never check a bag in your life.