vaterp asked: "My question though is I am a little intimidated by all the accessories and packaging options that exist on this site alone. I'm looking for some best practices/use cases for all of this."
And moriond responded:
"I suggest that you take a look at the Tri-Star Video page on the Blog, with a list of accessories that are shown in the video. The same video was posted in the forums, and there's a link to the discussion thread.
In general, I'd suggest that you get the Tri-Star with the Absolute Strap (which you can/will use with other bags), and that at the very minimum you get the medium Tri-Star packing cube among the packing cubes. (I actually recommend the full set of small, medium, and large packing cubes, with a possible alternative of using the convertible packing cube backpack for the Tri-Star/Western Flyer in place of the large packing cube; plus using a 3D Clear organizer cube.)
The packing cubes make organization and packing really efficient, and are sized to the travel bags. The medium size cube for the Tri-Star is sized to the (larger) front zippered pocket. It also works well for a number of other bags, in case you want to convert your Synapse 19 or Synapse 25 for general 1 bag travel with clothes. The 3D Clear Organizer Cubes can be used as your 3-1-1 toiletry bag, but when they first came out, I found I was primarily using theses for laptop power bricks and cables. Now you can get the same size bags with mesh sides instead of clear, or in Dyneema as light weight, general carrying alternatives. They easily transfer to other bags-- for example, into pockets in the now sold -out Imago messenger bags, into the side pockets of the Co-Pilot (possibly secured with key straps), into the bottom front zippered pocket of the Synapse 19 (and other places), etc. These are just very multi-purpose and handy, and transfer easily among the various bags.
If you want to use a pack-it folder or sleeve, the 18" Eagle Creek pack-its will fit nicely into the back pocket (though they're a bit too large for the Western Flyer). You can also forego the large packing cube if you're only packing items like slacks that can easily be held in with the straps (as in the video) plus using a pack-it sleeve, although I personally prefer to use the large packing cube.
For a really large number of cables and electronics, you can use the Clear Quarter Packing Cube. That's large enough to take two laptop sized hard drives side by side in each of the two clear compartments, without even accounting for the extra depth for cables, etc, but that kind of cube volume fits better in an Aeronaut or backpack with a large volume chamber. And an accessory like the Snake Charmer for cables and electronics also works best I settings like the Brain Bag or Smart Alec, or in the bottom front pocket of the Synapse 25. In most other instances I'd find it easier to use the 3D Clear Organizer cubes or their variants in mesh and/or Dyneema instead, especially for easy transfers to other bags.
Use padded pouches if you want the extra protection -- for example, for a portable USB DVD or CD drive. One or two small organizer pouches are also generally useful here. A lot of the other accessories are most useful when used with briefcase style bags (e.g. Freudian Slips let you organize papers and other accessories so you can easily transfer them from (for example) a horizontal messenger bag like the ID bag in the case of a Horizontal Freudian Slip, to your Tri-Star. In large backpacks like the Brain Bag or Smart Alec, the Vertical Freudian Slip (which does not fit the Tri-Star) can be even handier at getting to selected papers/folders.
Then, too, some accessories can double up functions. The Packing Cube Shoulder Bag is a general packing cube (about the size of the Aeronaut end pockets), that can also be used at your destination to hold light jackets, guide books, etc. It also fits conveniently into the bottom of the Swift (tote bag), or into the (now-sold out) Imago. In a Tri-Star I'd use this as an additional packing cube in the middle compartment.
I don't make much use of the Travel Tray, but this is good for quickly organizing loose items from your pockets or other pouches."