Here are some settings I use with my 450D-
Standard (for outdoor portraits)
Contrast -4
Saturation 0
Color Tone +3
Sharpness +7
Landscape (Brighter greens, yellows and blues. Can also be used for portraits)
Contrast -4
Saturation 0
Color Tone +3
Sharpness +7
Faithful (suits more for indoor shooting)
Contrast -4
Saturation 1
Color Tone +4
Sharpness +7
The Color tone setting can easily make skin tones quite red, even at 0 for the 450D. Interestingly, I don't like the skin tones with the Portrait picture style. Very pale.
The most convenient way for tweaking Picture style settings is to shoot a few RAW shots and then play with the Picture style settings in DPP. The settings in DPP have the exact same effect in the camera. With just 1 RAW shot you have all the picture style settings and options at your disposal. Eventually you should find a couple of settings that you can use generally.
Here are some customised picture styles for the 450D. Can be used with other Canon DSLRs but might not turn out the same. Be sure to test out before shooting critical events. Safest is to shoot these Pictures Styles in RAW so you can revert to Factory Picture Styles if necessary.
http://www.mediafire.com/file/nz53dzvm1jg/Faithful +4 Red Adjust2.pf2
Corrects red tones when using Faithful with Color Tone +4.
http://www.mediafire.com/file/df8p8on4s4ps2os/Standard +3 Green Boost.pf2 Corrects red tones when using Standard with Color Tone +3 with slight boost to Green tones for greener foliage. An alternative to Landscape.
I am currently tweaking a Picture Style to bring midtones closer to highlights for outdoor shooting. Still a work in progress.