The sparkles look kind of bad. They take away the focus and spread it everywhere.
- As for having her on the moon. I think the moon should look more "cartoon-like". It has a bit too much
realism and at first, I got the idea that it was orignally a round moon. There have been many images of a quarter moon
where the dark part is cut out. Celestia needs to be moved a bit more "on" the moon...she is still more in
front of it.
- The render looks awfully blurry here and there and the colors are off/odd. Did you do something to it? If yes, put all
effects on the render to nothing. It is better to work like that to get the colors and quality right. Do it as the last
thing since it is just a final touch.
- Perhaps you want to move Celestia a bit more in the middle or enlarge her if the render was originally bigger. A good
composition of the main element does half the work.
The swirls should be more around her instead of going off screen. It would do justice to the overal composition. Because
they're like lightbulbs in the dark, they can take off the focus very -easily- so beware. It's best to use
them around your main element and let it fade from the rest.
Working with black & white needs a lot of work. It is more difficult aswell because you need to be able to play with
the -contrast- in such way, that it still looks amazing when you set the wallpaper entirely to black &
white.
The idea is nice...but...if you're up for it. I do have a suggestion that would work for your whole wallpaper. But
it would need a bit more skill and to scratch all you have done so far. The elements you have used will still be in it.
It's just my own twist that I think would work very nicely. Because it is anime art, it is difficult to blend it in
with realistic things, therefore, you are able to use vector shapes. In Photoshop, it would work by just having the
circle shape used. You can make the clouds (I think you only needs 2 or so, make the clouds whole. Make the moon by
deleting or masking the empty part (to delete, you would need to rasterize it. Put everything more in the middle, the
moon a bit smaller. the cloud just in front of her and a little in front of the moon. You can use/make stars in the
background with a soft brush 1-5 px and dotting them in. You should be able to put the card symbols underneath the
actual whole image if you'd like. it should fit. for the clouds, get circle shape, press shift and just circle away
in a cloud-like shape. Set up transparency to your taste.
You can add the sparkles, textures for the moon and such later on. Hope it helps and you atleast get a clearer idea of
how you want to execute it. I personally think you should be using cartoon/artsy background elements because of the
render's style.