Irisalis Petals are one of the most important resources in Aniimo's current event, and spending them blindly can make your progression much slower. The biggest mistake is treating every event-shop purchase as equally valuable before securing the rewards you actually need. Save enough Petals for the main progression first, then decide how much you want to invest into additional rewards and Transmog-related items. A little planning can save a lot of unnecessary grinding.
https://www.mmoexp.com/News/aniimo-irisalis-guide-how-to-get-her-free-and-save-transmog-currency.html