I remember a very good piece of advice I've read: if you have to research a certain topic for your novel (navigation, local topography of a certain area, a specific historical period, etc), make sure you know more than what you strictly need. It's a lot of work, true, but broader knowledge makes for a stronger, more confident voice that will come out in your writing.
With fantasy novels, it's not so much about research as about imagination, of course, but the same principle applies: your background has to be broader and richer than what you actually let onto the pages. Consider how you feel when reading Lord of the Rings. You can just feel there's a whole magical world in the background of the story, just waiting to be explored. Tolkien had spent a lifetime creating his world, complete with mythology, history, geography and even a whole new language.
Similarly, you ought to invest time in your world. Live in your world. Create history and geography, draw maps and illustrate your novel (even if you can't really draw and don't intend your drawings to be published). Draw your characters. Perhaps write a collection of vignettes/short stories before sitting down to the actual epic masterpiece. I've spent years developing my world before I started writing Quest of the Messenger, and there's a lot of material which didn't find its way into the novels. Still, it's anything but worthless. The spirit of depth, richness, of a whole exciting world is there between the lines.
Here's a poem that did make it into Paths of the Shadow. It's called Upon A Stony Shore, and tells of a legendary queen named Thasiella:
One night, when waves were rolling in
And moonlight was no more
She wept, the lovely golden queen
Upon a stony shore.
"My love is gone," she cried in pain,
"My husband and my king,
But I shall walk with him again
Upon the fields of spring."
A cup she filled with bitter brew,
"Leave me," she gave command.
But there was one with her who knew,
And dared to thwart her hand.
"My queen, if you would take your life,
Than mine shall go with yours."
And out she took a silv'ry knife,
This maid of no remorse.
"Your love shall wait, a golden crown
Like sunlight on his hair;
In Lands of Everlasting Dawn
He dwells, he goes nowhere.
Your people need you, my fair queen,
'Twon't do to lose you both.
Unbar the doors, let people in,
Tell them they have your oath."
The poisoned cup fell from her hand,
She thought of death no more –
And thus did Thasiella stand
Above a stony shore.