Nothing. Just swap breeding in Sun & Ultra Moon in hopes of getting one of those Magikarps to Shine.>recent success?
In Sun, got my first and probably last SOS shiny with a rare call-rate: Dhelmise.
Synchronizer failed, but luckily the Nature it got was still competitively usable.
In Ultra Moon, hatched a Ponyta through swap breeding, my first Shiny hatched in this game.>ever drop a hunt?
Probably, although nothing specific is coming to mind.>how do you react to shinies irl?
If it's been a long hunt: Yes! Finally!
If it's a random that I already have: Aw, damn! or D'oh!>did a bad play ever cost you a shiny?
Yes, and multiple occasions.
Worst ones that come to mind are Solrock in Ruby, Zubat in Leaf Green, and Gogoat in Y's Friend Safari.