Three things make a fantasy epic work for me. 1) A complex plot with plenty of twists and turns that comes to an explosive climax. 2) An imaginative magic system and setting that feels both real and wondrous at the same time. 3) Deeply personal characters dealing with issues that transcend genre. (This is the most important one.)
I approach my writing from that above philosophy. I am probably best known for my magic and my settings, where I try very hard to give the reader a unique and different experience, one they haven’t gotten from other fantasy books. I am also known for my endings, where I try very hard for well-foreshadowed–yet still surprising–twists and climaxes.
However, magic is only as interesting as the characters who use it. A plot is only gripping for me if I care about the characters. Danger and action sequences mean nothing if we don’t CARE about the people who might be hurt or killed.