My part of the cake:
This was the first time ever that I did a water simulation. It was a tricky task due to the fish going from realtime into slow motion, so the simulated water had to be retimed. And when everything ends up in a freeze frame, you can see every drop of the water.
Thanks to the amazing compositors at Fido, Daniel Norlund being one of them, it turned out quite all right in the end.