I often look at the professional fantasy artists work, often available in the form of books and art prints for valid reference on fantasy art.
Magnificent paintings that look realistic in terms of photo realistic skin tones and photo referenced paintings that most professional artists use.
Boris Vallejo
It's from these professional artists that we can learn more from and their art should be studied by us to gain a better understanding of how to...not necessarily drawn and paint exactly like them, but take our own piece of inspiration from them and create our own ways of creating fantastic fantasy art.