There is at least one person on the Fantasy Flight forum and/or BGG who has done engine glow labels/stickers for all the big ships: Decimator, both YT freighters, lambda, etc. Those could provide inspiration, or perhaps just ask the guy if you could use them?
I think I saw another person who was doing all the markings like you have for Red 2, Red 3, Red 5, etc. But like ALL the markings - so you could effectively just base coat an X-Wing and wrap these around it. Maybe you should find that guy too.

Black Sun is good. Do the Hutt Cartels have anything like that?
Ace/kill markings. Can you print this small?
Nosecone/pinup icons. There's one in particular for Azzameen, I think it's a Firespray (the Andrasta?). There's also one of the unique Scum-faction Z-95's (N'Dru maybe?) with a hotrod-type paint job. And Kath Scarlet's gang has some pretty intricate markings.
Hazard stripes and checker patterns are generally useful. I guess I could say the same about racing stripes or other 'generic' squad markings. You know, because someone might want to make Fuchsia Squadron or whatever.
- H8