I'd like to talk to you about the importance of post editing in 3D art, in my most humble and modest opinion.
Sure, not everyone has the time, or the will, to make the best of the pictures you render for you games, or for just the art you produce.
And, sure, not everyone knows how to do it.
Little parenthesis; let me just say that this post isn't, in any way, a critic on any art from fellow artists, either posted on this forum or anywhere else. It's just that I felt the need to comunicate to whomever is interested my conclusions about post editing.
Here's an example of something I just did minutes ago.

On the left, a pic of our most belove deviant redhead, rendered in DAZ3D with Iray engine. Two lights, one warmer but softer in front of her, and a second, brighter and colder, on her right. It looked good after rendering. I was satisfied.
But never be satisfied without trying to edit it, even if only for a minute or 2.
(I use Photoshop but I believe there are plenty of other software out there)
Put your picture in Photoshop (for example) and play around with it. Here, on the right is the final result. Well, I got from satisfied with the render to just Yeah... What seemed a cool render looks now, to me, rather bland.
I did nothing fancy, just a few minutes in Photoshop. Played with levels and brightness to bring more light, contrast and vibrance to add more colour. Sharpened it slightly too.
There is no step by step technique here. It's your subjective taste that will dictate what feel and mood you want to imprint on your picture.
The render took me 1h40. The post editing less than 5 minutes.
It's possible to obtain the same result in DAZ3d but trial and error, render after render, but, in my most humble opinion, you will gain precious time and enjoyment by learning a few basic tricks in post editing.
And there are tons and tons lot more tutorials out there for post editing.
Sure, for games this will add a lot more work. If your game has 1000+ pics would you post edit each one of them? Well, in my case, yes and no. I've done it, a lot. Brighten a midtone level +20 for each of the 100+ pics of a particular scene. Lots of time. But I think it's worth it.
More so if you do renders for just one picture. And it's fun to learn and practice post editing no?

I am no master, not at all, of Photoshop, but, as always, feel free to ask your questions here on the forum and I, and lots of great fellow artists will surelly help you out. Just try to find a few tutorials on youtube or other sites first. Not that we don't want to help you but the guys that make those tutorials are, in most cases, professionals. And know better. Better than me, at least.
Cheers!