I found this article describing what makes a good puzzle, and it references several puzzles which, as best as I can tell, were designed for something called the CiSRA Puzzle Hunt. However, the website they link to is down, and I can't seem to find anywhere that's hosting the puzzles. The Wayback Machine works for 2009, but not most years. Does anyone know if these puzzles are still around?
The Wayback Machine seems to work for other years -- here's the link to 2012, for instance. The site (including the archive of puzzles) seems to be completely usable to me through the Wayback Machine.
Mezzacotta (the successor to CiSRA) posted the 2007-2013 CiSRA puzzles on their site a couple days ago: https://www.mezzacotta.net/puzzle/cisra/