Sometimes it's difficult to find a new source of inspiration for a particular project. I find that happens both as a writer and an artist. (I use the term "artist" loosely, since I haven't really drawn anything since HeroMachine 2 came out...) But there is inspiration waiting for you everywhere you look, if you just find it. I recommend taking a notebook to work, assuming you don't have anal-retentive bosses who hate notebooks. (I've had a few...) Jot ideas down as you go through your day, no matter how ridiculous. (I once had an idea with little meadow creatures who dueled with feathers, but I ended up dismissing it for its similarity to Redwall. You know, that immensely popular series with little critters acting medieval...?)
Orson Scott Card, the famed author of science fiction, fantasy, and dabblings in other genres once said that a good story starts with two radically different premises that work against each other to create conflict. (No, this is not a direct quote, I'm just typing it the best I can remember.) His book Ender's Game pitted a plot of teaching children to be military geniuses against a plot of invading aliens. And he included at least two major plot twists towards the end whose consequences reshaped the story entirely for the reader. His story has since won numerous literary awards and is studied by military academies for its insightful look into military training techniques. The point is, he created an awesome story with two opposing ideas, neither of which would have been promising material without the other.
(I gotta come up with some new material...)
The same can work in character design, if only in the planning stages. Take my usual example, Fierra. I was thinking of doing a fantasy story, but didn't just want elves and dwarves. I wanted to be different! So I would make up my own. I started with the idea of a lancer from Final Fantasy. A group of lancers, who live in the woods. But a whole group would be silly unless I made them into a new species. So I created the Feyrune, a group of cat-like lancers, only to have that idea squashed after I found my friend playing FFX which has.....a species of cat lancer! Infringement! (And doubtless the software giant Square-Enix would crush me if I tried to fight that one...) So I had to go back to the drawing board. Jumping creatures, jumping creatures... Kangaroos! So my Feyrunes were now sort of kangaroo-based. Over time I added to the mythos when I cared to.
But that didn't do much for the character herself. She was just a cog, not a character. So I started imagining (with the help of HM, of course) what kind of character she was.
She was wild, untamed in comparison to her peers. (Crazy hairstyle, check.) She was a minority among her people, a common breeding, a mongrel. (The fur patterns I have yet to manage in HM3 after all the other stuff gets done.) Her attempts to fit into her society continually failed, her hard work to be accepted as an equal only led to disdain. (Fierce expression, check.) Their disdain causes her to dress more revealingly than other females, especially since most females don't join the armed services. (The low-cut leather of HM3, the midriff-armor in earlier styles.) Her daring style of dress is both an affront to the more traditional members of her society, but also shows her recklessness. (Armor protects less of her, double-check.) Even her halberd weapon made her unique, as I imagined someone of her independence not wanting to use a bought weapon, so she forged her own. (And carved the staff.) By the time the other heroes meet her, the community is glad to be rid of their "trash," while she is by now the toughest and most determined of her people.
A kangaroo person who lives in the woods and is a rebel hated by her whole people? Now that's a character arc! In comparison to the wooden character I originally wrote her as, anyway. But the character traits I wrote decided the whole picture--the animalistic appearance, the dramatic attack pose, the costume itself. All the little details add up, especially the subtle textures to increase the realism. (And the time that went with them. Ugh.)
Don't be afraid to experiment and get it wrong. Professionals get it wrong all the time! The only thing that makes a professional is time and endurance. Orson Scott Card says you have to write ten thousand bad pages before you can write something good! (Again, not a direct quote, in case he said "words" instead or something. And this is freaking true--I found some old floppies from high school and read my old drafts of stories until I wanted to cry in shame.) To prove this point, his website hatrack.com has something like two dozen online writing lessons, and in one of them he showed the actual drafts for one of his books. It took him four tries just to get a good first chapter he liked--but what a first chapter he ended up with, in comparison to the first draft. And each new draft gave him new ideas and new material to work with, until he ended up with events and characters that would echo through the next three books as well. Though they weren't always there, you could see their lasting impact on the young protagonist's life.
So go on. Don't be upset when it's not right the first time. Real art is the product of hard work and suffering. Believe me, I do those parts every day trying to get the things I want for my stories. But if you want something done right, do it your--I mean, if it's worth doing, it's worth doing right--I mean, genius is 1% inspiration, 99% perspir--I mean, it ain't over until the fat lady--
If at first you don't suceed, try again! And keep trying until it's right. All it takes is time.