[ART] This is driving me nuts

[Acies]

I suggest watching this:
http://cg.tutsplus.com/tutorials/photosh...-textures/

Ultimately better than if I were to (lost some sections of my own attempt of a tutorial, so no-go). If I'm able to succesfully create something which might help you I'll get back to you

Edit:
To critique your texture(s):
1. Model itself seems to be a 'reduced high poly model'. The mesh itself is all kinds of odd (in a bad way).
2. The diffuse is mainly black and white, quite grainy.
3. The normal map seems to be generated from the diffuse map - not good! So much noise on it, unnecessary noise.
4. The specular map also seems to be a generated map, with a lot of noise. There is no gloss either ~

You are not adding 'detail' by making your textures grainy. It's only bad noise which doesn't really belong there. There can of course be a lot of things going on in a texture, but everything has it's place there for a purpose. Eg. 'that edge of the screw has been unscrewed several times, so there is wear and tear on it' or that 'ventilator for the coffee machine has exhausted coffee particles, so there is forming dark brown dust around it'.

Thinking about purpose, not just adding dirt/details randomly, is important to the process of becoming a better texturer.

Creating a good high poly model (depending on the type of model requires different tools) is very important in most texturing cases. It is not necessary in some cases; hand painted 'stylish/cartoonish' models.