Well, just put all your graphics options on your gfx card on max, get all the high res addons you can get, and put lfs to maximum detail (one tip, make a seperate install for this, or it gets very tiresome to change everything everytime).
Then just make a couple of screenshots, always save them without any compression, and open them in any image editor.
I always was taught to do the sharpening first, and everything else you deem necesary later. Also, don't overedit it, it has to remain real. If you watch my earlier pics you see it was a little bit overdone, but the blackwood pics are quite nice I think.
Btw, I used picasa for these pics, because I'm still too lazy to install cs2 on my mac (i'm an expert procrastinator
).