First, make sure no voidwyrms are nearby, as they will try to kill you. Next, pet the Astrodelphis. Finally, put element in the last slot of your hot bar and start feeding it to the Astrodelphis. Thanks for reading my tip!
Build an argy trap in the space bridge. You know, 4-5 gate frames in a row with gates at each end, like a tunnel. With enough space between for you to run. Fly up to it and let it “aggro” on you (give you a friendly nibble) then fly to the trap and let of follow you inside. Close the gate. Soooo much easier to tame this way. No more flying off between bites.
U have to pet it and feed element. The amount of element goes up each time u have to feed, but the taming bar will fill up faster. Easy element u can gather by using an anky or pickaxe on the blue crystals in the space between the bridges. In the center of the map