Well I don't think you need to go and make an all new race, but you should at least justify why things are the way they are, instead of just assuming that elves are elves because they are. For example, if I were to write a quick and scrappy back story for the elven race...
There was a time when gods would command legions of followers into battle, and of these the god of humans rapidly grew his forces into an unstoppable fist. The human race grew to power, and became a dominate force, but few were pleased with these arrangements. In the shadows, a sinister lord of demons plotted the destruction of the human god, and his army of colossal oni would lay waste to the human cities.
Battles rages throughout the realms that bask in the light, but over time the demon king was pushed back into his eternal darkness, and so he sat, and skulked, and watched the humans from afar, filled with a envious rage, and as he watched, he came to understand why the humans were able to defeat his minions.
Every day, the humans would ready themselves for battles that may never come. They would spar against each other, and fire arrows at scare crows. They would read over vast books on war tactics, and tone themselves by playing sports. They were more than they were made to be, because every day they fought, so that when war would come, it was a day like any other to them.
The demon king looked at his own forced, that were little more than large animals. They were given all the subsistence they needed, and slept for thousands of years at a time. They were lazy and weak, and would never stand against the human forces. They needed to taste blood, were they to ever demand it.
And so the demon king took the elemental forces of his realm, and from them he crafted a sacrifice to his own follows, a new race that resembled the humans in figure and stature. He filled them with zeal and determination, the gifts he had neglected to give his demons.
He then gathered this new race that he called 'Elves' and appeared before his sleeping demons. With a great voice to shouted, and they awoke to his voice.
"You are all lazy, ungrateful beasts!", he proclaimed, "You could not even beat such puny animals! You are all worthless to me, and I have a new chosen race now, crafted in the image of those that destroyed you!"
The demons rose with anger, and envy. Their master was their own, and their pride would not allow them to share his vision. They attacked the elves, just as the demon king had planned. There was no battle, just a blood, as the mighty demon forces tore apart the infant race. They were no warriors, and not ready to stand against such an army. Those that could retreated back, hoping to survive the fury.
The king of demons watched as his pets tore apart their new toy, then slowly, one by one, returned to their slumber. This angered him, that his attempts had been useless. His forces were no better ready for battle than they were before. While the human forces he sought to over come were warriors armed with sharp steel, his elves were little more than weary vagabonds. He would need to give them a chance to grow, and become strong, before they were to serve their use.
So he made a gambit, one that would either destroy the last of his elves, or allow them to meet their potential. He opened a rift to the realms that bask in light, where the humans and others were waiting for them, and he hoped that they would survive the righteousness of the human race.
There, the humans looked upon the first elves not as enemies, but as brothers. They were similar in form and figure, and shared a common hate of demons. They were welcomed as guests in these worlds, and were allowed to build their camps, to become towns, to become cities. This pleased the dark god of demons, that his eternal slaves would be safe within the house of his enemy. He once again appeared to them, and they listened to him speak with open ears.
"Your homeland is held by vile savages!" he told them, "Would you disgrace yourselves and me by allowing this? If you will still honour me, then you will pay tribute to me! Every night that the moon is taken by my touch, and dares not shed it's silver over the landscape, I will open a rift to your true home, and you will march through the wastelands to my home and temple, and there you will pray!"
And so it was that every new moon, elves warriors entered the realm of shadows, and marched through the waste towards the great temple, but they were always challenged by the demons, who now dare not sleep, lest their god choose these infants over them. And the demon kind sat, and he watched as the elves grew to become a might race, wishing to serve him, and as they grew stronger so did his chosen race, the demons he had crafted before time, and he smiled.
See, elven mythology without all the cliché.