Hi manz,

yesterday i made some material tests to see what helps making a material looking good. Here is the result.

1.)Most important is a good lightning.
Using a physical sky or a hdri is a good way to achieve that and of course using global illumination.
A bad lightning situation destroys an image. There has to be bright areas and dark areas(shadows).

2.)not less important is the use of high quality texures. This is a bit trial and error. What looks good in this renderengine doesn`t look good in that one. The bump map is important when the mainlight is not coming from behind, which it shouldn`t do in any case, because this destroys threedimensionality.
The bumpmap has to fit the colormap. Often that is not possible and it looks odd. I do my bumpmaps in photoshop using the highpassfilter and sometimes painting in some darker areas where should be the bumps.
A reflection or specularmap is also important, because as a result you have reflective and nonereflective areas. Using fresnel effect for reflective surfaces also does a good job. Please look here:

http://moi3d.com/forum/index.php?webtag=MOI&msg=1568.46

3.) i give every material reflective properties. Often very low and blurry.It`s also here a bit trial and error.

I think these are the most important things i pay attention to.

Greetings
Dirk