Perfecting Potions is a two-part quest given by Magnus. This quest is given immediately after we complete Magnus' Rescue Bluebelle! quest, and it will require that we are at least Level 21 (the level at which the Alchemist becomes available) in order to complete it.
As soon as you complete this questline, you'll be given the three-part Making Scents questline, also by Magnus.
Part 1 of 2
Part 2 of 2
Michelle's Note: making two dragonwing potions can satisfy not only a portion of Part 2 of this quest, but also the entirety of the A Consolation Present quest given around this time by Yvette. So try to time it so that these two quests are running concurrently! In addition, once you've crafted those two potions, I recommend hanging on to them for a bit, despite the fact that Myra will undoubtedly try to buy them from you. Reason being, you will likely soon be starting Bluebelle's Asking the Oracle quest which will, once again, want you to make/have two Dragonwing Potions!