Yeah, definitely don't lock onto to anything during dragon stage. The hardest part was learning which 'flight' was flame breath and which was just him flying around like an asshole, but the simple solution is to just assume it's death from above every time. I think the roar the dragon makes while taking off is the key to knowing what he's about to do, but I beat him before I was sure about that. The crackle of lightning telegraphs the worst moves NK himself does while on the dragon too.
And I definitely did not know what I was doing with the weapon. I beat Yhorm before I realized you could charge it and let go of L2 to move around freely, so I'm sure that had a lot to do with my dozen or so failures.
That was another weird area. I died more times to the miniboss on the way to Smoldering Lake than I did to the boss at the end of it. And the fucking worm literally just attacks the air in front of it if you come from the bonfire behind, to the point where it's practically impossible to take damage at all during the fight.