Ah, custom deliveries: Final Fantasy XIV Patch 5.3 has added yet another character in need of assistance, and you’ll need to either fish, gather, or craft for their affection. Ehll Tou’s custom deliveries are unlocked within The Firmament, which is accessible to everyone who has unlocked the Ishgardian Restoration.
Ehll Tou’s Custom Deliveries are unlocked in Ishgard within The Firmament.
Before taking on custom deliveries of any variety (including Ehll Tou’s) you’ll first need to complete “Go West, Craftsman” Considering Ehll Tou’s custom deliveries require you to be at least level 70 you should have the prerequisite story quest “The Better Half” completed. Just pick up “Inscrutable Tastes” in Ishgard if you haven’t already (this unlocks Collectibles), then head to Mor Dhona and talk to Lydirlona (X: 22.3 Y: 6.8) to grab “Go West, Craftsman.”
From here head to The Firmament in Ishgard. If you haven’t already unlocked the Ishgardian Restoration you’ll need to do that first (the guide linked will catch you up on that front). Once inside talk to Ehll Tou (X:13.5 Y:11.2 – he’s the child dragon): you’ll either have to finish his side quest “If Songs Had Wings” if you haven’t already, or you’ll grab “O Crafter, My Crafter” if you have. Once you’ve complete “O Crafter…” you’ll unlock custom deliveries for Ehll Tou.
These work like all the other custom deliveries in Final Fantasy XIV: Ehll Tou will have a list of items he requires, and it’s on you to grab them. Remember, you are limited to 12 custom delivers a week across all the available NPCs, so if you’re still wrapping up your progress with some of the older ones then I advise doing so prior to assisting Ehll Tou.