I like how you're leading the viewer with your shapes. You could add a bit more marginal since now the composition is a little tight.
A light source that is coming directly from the left gives easily a flat feeling. Might be more interesting to have the light coming from an angle. Also, try using warm/cool color contrast when shading. That means warm colors for highlights and cool colors for shadows. Or you can do it the other way around too.
The claws could be darker since now they create lots of contrast.
I really like the dynamic feel of this picture. There's a real sense of movement. You've clearly used reference for the horses, which is always a good idea.
I've no complaints about the composition, but the texturing could be improved. Now most of the texturing is for the grass, which is hardly the center of interest in this picture. Try introducing more texture to the horses, and also avoid using soft brushed since they give you a result that is too smooth.
You can also try to harmonize the colors you are using. I see you have warm highlights, but the shadows are neutral black. Try using cold colors in your shadows. Also the god rays in the top left corner are cold even though you've used warm light everywhere.
For painting more realistic fire you could try collecting reference photos of real fire.
Your paintings are amazing, they show a lot of depth that adds a lot to the scene. The way you use color, and the colors you use just scream whimsical fantasy. I really enjoy them! I would absolutely love some advice on my most recent water color, I wanted to make it stand out a bit more, but I think it fell flat.
The anatomy of both creatures are really good. If you want to achieve more depth, you should try putting the centaur into perspective instead of using a view directly from the side. Also, using some color perspective always helps with the depth.
The composition would be more interesting if you didn't simply cut the picture in half. Also, most of your lines (including the imaginary one from the horse's gaze) are leading the viewer outside the picture. Here's my composition tutorial for more details: [link].
Like you said, the colors work well. The composition has everything interesting in the dead center, but it's not such a problem in a picture like this. What does bother me is the perspective. The instrument is shown from the top, but Shiva is not drawn from the same angle.
There are several things you've done exactly right here. It's clear that you've paid attention to the composition and the colors. I think the shadows could be even more of the same color as the sky.
The picture could use more depth. What makes it look flat is the background mountains being as warm and bright as the foreground. If you add some color perspective you would gain more depth. You can do that by fading into the sky color by gradually making things colder and less saturated the further an object is.
The picture has a nice flow in it, but otherwise the composition can be improved. Here's how: move the head out of 'dead center' to one of the spots defined by the rule of thirds. See my composition tutorial for details: [link].
For the shading you should use colors instead of black and white. Since the background defines the ambient color as blue, all the shadows should still reflect some of that color. Also to get nicer color contrast, try changing the light in the left side from neutral white to a warmer color, and then use that same warm tint in your highlights.
You would get nicer texture to your painting if you use textured brushes instead of just the soft round one. Also to get rid of the digital look you can add an overlay layer on top and add noise (in Photoshop it's in the filters). Then adjust the layer opacity to get the desired amount of noise.
A scene concept for a DnD characters lifestory. Unfortunately the game never took off because the rest of the players lost interest while I was gnawing my way through the 4th edition sourcebook.. This one took me about 30 hours to finish (with most of the time going on the wood patterns) but in the end it still didn't turn out the way I wanted it to, especially color-wise...so I figured I might as well post it here, seeing as I'm quite the admirer of your work.
The details and the fur looks good. I think there are some problems with the lighting. The blue light in the background would require very low intensity light and lots of fog to look like that. Most of the time a backlight shining directly towards the viewer would look almost white and most of the times would be the brightest value in the whole painting.
Looking at the cast shadows there seems to be both front and back lighting. The trees are only shaded with the front light. Try to use only one main light. In this piece it could be the light shining behind the trees at the back left.
The girl's face also needs more shading. Now it looks flat and cartoony. Checking the values by desaturating the painting might help.
The snow has too much yellow tint in it. None of the light sources are this saturated. Try to be more subtle, but still keep the warm/cool contrast.
That's very good for your fourth digital painting! The hair looks good, but you should still soften the tips of the hair and even smudge some of the hair details. Also the black line on the upper lip bothers me, but maybe it's intentional.
You've used colors nicely on the skin. Some areas of the face still need more red. The lower part of the nose and the cheeks are usually quite red.
Overall you've been overusing soft brushes. My recommendation is to stay away from those for now and only use hard edged ones. I know it's painful at first, but it will pay off. Also you should avoid shading with neutral black. Instead try using warm colors in highlights and cold colors in shadows or the other way around. That will give you more natural effect.
As for composition, try avoiding the 'dead center'. Here's more info: [link]
The fire is missing smoke. Try referencing some real fire to get more realistic results.
I hope this didn't turn up to be too negative. I've done all the mentioned mistakes myself, and a lot more!
You have achieved a colorful look without going overboard. The colors look harmonous probably because they change so gradually, except for the red dress on the right, which can be thought as a point of interest. And it's ok as long as you keep the number of focal points small. However in this piece there are too many of them, and they are not well positioned, and it makes the picture messy.
An easy rule of thumb for placing your points of interests is to use rule of thirds. I've written a tutorial on the subject: [link] .
Keeping detail near the edges easily leads the viewer out of the picture. This happens especially at the lower right corner on this piece. Also, viewer usually follows the gaze of the characters, and here the character on the left leads it again out of the picture. Flipping it would lead it into the picture instead.
Even though I like the colors, I would still desaturate parts of this picture. That way you could spice up the areas you want with intense color. When everything is saturated none of the areas look bright, but if it is surrounded by desaturated colors it starts glowing.