I don't know, what should i say! XD
Just draw, or take a Picture of smaug and try to draw him! I'm not a teacher! XD
The only onw which i could say is: Imagine a big badass lizard with spurs and co!
I like the angle and the sahdows on the first one, and the many details on the second one.
He is fire. He is death. Get over it.