I usually leave Optimize Image at default: tried extra saturation and sharpening but later found that it is easier to adjust later. For that reason also, I would shoot RAW.
I try to use highest shutter speeds (except for props) - especially if using non-VR lens.
I did not have much luck with ISO over 200. I have heard D80, 200, 300 are much better at that.
Maybe you could post some of your photos in this thread?
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