Some random drawings and pages from my sketchbook. Some of them I coloured up a bit in photoshop.
Armour, for dragons and people. The bottom two drawings look like ceremonial trappings to me, I can't imagine those shoulder pieces are very mobile. As for the dragons, I don't imagine them wearing anything heavy, or anything made of metal for that manner. So they wear leather instead, skinned off the very prey they hunt. It's lightweight and won't heat up and scald them when subjected to blasts of fire.