Before you go changing settings randomly to slightly adjust to how your eyes like the image, well OPTIMALLY you would need to start at a reference level calibration.
It is not NECESSARILY wrong to POST-ADJUST the image after a calibration to your own liking (sharpness, color saturation, whatever), but you should have one mode in the projector calibrated if possible. I understand it is too expensive for some of you to calibrate a sub-$1000 projector with decent equipment (like a D3 + ChromaPure), but it's still nice to do if you can.
It just makes more sense. Some movies were just shot poorly or have issues and you could in some cases improve the image by post-adjusting away from a calibrated image. However, in most cases it's easier just to leave it alone, but possibly change the GAMMA slightly on a movie as some movies have bad gamma mastering causing problems.
As far as what looks right BY EYE, well that is SORT OF impossible because most movies are not filmed with neutral D65 overhead lighting. The neutral white point is actually only if the camera is perfectly balanced itself (or post-corrected in editing) such as being filming outside under the noon-day sun (or using a non-natural D65 source). Furthermore, you are only adjusting what looks right in that one scene even if you are watching "perfectly filmed" reference level D65 color neutral whitepoint camera work.
I said some confusing things there, but basically:
1) I wrote a post for newbies / layman people to easily understand how the color works on our projectors:
2) If you don't have calibration equipment, then at least use the AVS Rec 709 Disk which is a free download from this Forum. Some other disks you can purchase include the Disney one, the Spears and Munsil, and the DVE calibration disk. I own all of these except the Disney one (well probably have that one just never used it). Use these disks to do whatever you can, but you won't be able to get the color perfect without calibration equipment.
3) After Step 1, just do whatever you want to the image, who cares
4) Eventually buy calibration equipment and do it right, then hit yourself and say DOH!