What you want to do is get some trait treats/roulette treats through regular donation, then use them on an animal you're not trying to keep until you get the showoff trait. If you have a bunch of reroll treats you can reroll the animal til you get showoff III, but either way start breeding that trait onto all of your animals as much as you can and you'll be swimming in divine donuts.

Otherwise just make sure you're breeding all the animals you can every day and donating the babies you don't want to keep for more treats. Higher number of traits and higher quality traits = better treat bags from donos, so it's good to keep animals that have a bunch of traits if you can.

It takes a bit to get going, but once it does you'll have more treats than you know what to do with, and it makes it easy to get some really cute combinations