I've made this:
into this:
Here's a simple tutorial on how it's made. I'm not gonna write exactly what I did in every step, the point is not to redo what I've done but to understand the technique. No artistic skills are needed but knowing GIMP (or Photoshop) is important.
1. Preparation.
The first step is to resize all the textures to a size that makes it easier to work with. In this case 512x512 for the torso parts and 256x256 for the addons.Later it can be resized back to half of that, as it is always easer to make an image smaller then making it bigger. No matter what engine is used always stick to power of two when it comes to texture size, so 32x32, 64x64, 128x128, 256x256, 512x512 and so on. If the texture is any other size then in 99% cases it will be scaled up or down by the graphic card driver and that take time and memory.
If you got all your images the right size, put them all on one sheet in one file, you won't have to reproduce all the steps again and again you'll just do it once.
2. Get Good textures.
For this one you will need two good looking textures - metal and leather. Use whatever you have or google for them.
I found this leather texture:
And these metal textures:
That I've combined into one:
All these textures are seamlessly tilling (or try to be).
3. Mix and match.
Make a new image, in the first layer paste one of those textures (metal for example). Make it so that the texture will fill the whole image, but not stretched but tilling. You can use the bucket fill option for that.
Now add a new layer (transparent) and paste all those textures we want to change that we prepared in step 1.
You should have a two layered image something like this (I've used the eraser on the top layer to show the bottom layer):
Use the eraser tool set to 20-60%, with a soft edged brush, to remove some of the upper layer, so that the lower layer will show. Use less in dark and black places, these are usually details that you want to keep, you can go all the way in places where the colour seams uniform.
Do the same for all metal parts.
Once that is done, merge the layers and repeat it with the leather parts and the leather texture in the exact same way (you might want to change the hue, brightness and contrast of the leather texture).
4. Spectacular highlights.
This is an important stage for metal textures and metal textures only.
If we were using a shader for metallic parts we would have to make a separate texture for that, but we are using all-in-one texture so we have to bake that into our one texture.
Use the texture from stage 1. Turn in into grey-scale (desaturate), play around with brightness/contrast until you get something like this:
I've also deleted (painted black) all the parts that are not metal, we don't what them to shine.
Paste this in a separate layer on top of the texture you made in step 3. In the layer mixer, change this new layers mode into Brighten (in some cases "soft light" or "hard light" might work better).
5.Adding details.
Basically your done, but you can still add some details, this is just a matter of cope-paste-scale.
I've added a belt this way, but unfortunately I had to deform it to fit the Uv's, GIMP is not best at that
Base belt texture:
Scaled and bend to fit:
6. End.
Once it's done, merge all layers, cut it up and save. Put a fork in it, it's done!
