I always liked the Xenomorph, and drawing them is a challenge. They're really complex but the color scheme is simple - in this case it's just a blend of black, white, and dark blue/grey. It's not a hard technique once you've got it down, and I've been teaching a few people in Discord sessions if you're interested in learning it.

There's a timelapse of the process demonstrated here: https://www.dropbox.com/scl/fi/qmw8fgezji6b5ytxbgvt8/Xenovid6Compact.mp4?rlkey=twtlt1wqg0ayo5oa1iettvwrq&dl=0