Just a few Tips:
A 'tidy' directory folder structure helps a lot when putting a large Model Pack together (for yourself and the users of the Pack).
NOTE - Avoid putting too many folders within folders.
NOTE - Its best to group your corresponding media into a single folder (one for segments section,one for entity section...)with the name of your Pack (keep this as short as possible).
Keep 'address's' (in the FPE and FPS files) as short as possible by avoiding long names for the media.
Try to keep 'all' the media 'Icons' looking the same (White backrounds) with sharp clear images (not always possible).
When the Pack is finally compiled 'TEST EVERYTHING' one more time just to avoid having to supply any 'Fix Patch's' at a later date.
Compile a short 'Contents List' of the media in the Pack and also a seperate file with a short 'Description' of the Pack which you would like to see on the final web site page.
NOTE - I just use 'NotePad' but check the spelling and Grammer is correct.
Supply a folder with some clean 'screen shots' which should be 640x480 in size.
If possible, compile a video of some of the media (in game) then upload it to a video site (Youtube,Vimeo...) and then just supply the 'address' of the video to TGC along with your other 'Document' type stuff.
I recommend constructing a 'PDF' Manual for the Pack if there is any extra or specific information you would like the users of the Pack to know about which also helps cutting down too many unnecessary questions being posted.
Packing All Final Media before Submitting to TGC
NOTE- Create an 'exact' copy (empty folders) of the FPSC 'Files' directory and then place 'your' final media folders to the corresponding locations where they should be 'within' this.
X1 Folder containing your 'Documents' stuff (Contents List,Description,Video address,Pdf Manual....)
x1 'Screenshots' Folder
'Put all of these into a single folder with your Packs name and 'zip' it up for uploading.
Overall, its best to have 'All' this media together (ready and tested) before you submit it to TGC for sale.
I hope this helps and wish you both the best of luck with the Pack.