Congrats on the purchase. Although I don't have the same model as yours, I can give you some ideas as a starting point. I did these things when I got my EX501 and am enjoying a great picture.
1) First, acqnowledge that what looks good to me may or may not look good to you or somebody else, etc. So experimentation is key.
2) Most of the settings from the factory are tailored to the environment at the stores, meaning to0 bright, way too bright. This means that almost every setting may be cranked up compared to a home setting. You turn the brightness up, you have to turn the color saturation up, etc.
3) On my TV, I turned the backlighting way down, increased contrast, reduced color saturation, changed the hue to have more red (faces were too yellowish).
4) Sharpness is a matter of preference and also dependent on the quality of the source signal.
5) My brother just got a 52" NX800 model and he seems to like the picture as is out of the box. Now, I haven't seen his TV yet. When I do, I may not like it as much as he does, but it's his TV and his eyes ...
I also want to mention that my preferences are influenced by my old photography background (I mean film not digital). We used the adage "expose for the highlights and let the shadows fall where they may".
Good luck and enjoy.