Favorite non-System parts for space MOCs?

[murphy_slaw]

After a long dark age, I came back to Lego and started collecting and building again. One of my favorite themes that came out while I was away is Space Police III. I especially like the way that some sets (Raid VPR, Hyperspeed Pursuit) integrate Technic fairings alongside System parts.

When building Space mocs, are there any non-System parts that you like to include in your builds? (I'm thinking of more specialized parts than technic beams or simple bionicle ball joints that show up in many official sets.)

[Space Police XVIII]

https://www.bricklink.com/catalogItemPic.asp?P=98589 makes a halfway decent missile or drone body.

Technic panels are great for curves, like you noticed; Bionicle armor shells can also work.  https://flic.kr/p/TmUW6V

For that matter, Bionicle wings are good, and the bones/shells are great for mech building.

Also, welcome back, congratulations on turning back to the Light, or something like that