Some of the challenges I had for making the donut scene was simulating the icing in the bowl correctly, as it would come out really weird and it would fall through the bowl. I also had an issue where the sprinkles on the donuts were disappearing as we switched into Blender 2.8. I overcame the fluid in the bowl challenge by correctly timing the fluid animation as it fell into the bowl, and I overcame the sprinkle challenge by making sure that the sprinkles on the donut weren't entirely dependent on the sprinkle group within the Blender project, where they were all made.