When converting the color space into CMYK using Adobe Photoshop, remember to set the preferences for your particular printing environment in order for the separation to be accurate. Don't shoot in the dark; prepare the image for the particular output device to which you will be sending the file. Ask your printing service for tips on making separations for their press.
Once all sizing, cropping, color correction, touch-up and creative enhancements have been made, apply an appropriate amount of Unsharp Mask (Photoshop). Filters such as Unsharp Mask depend on image content, and are best applied when the image is at final resolution and dimensional size.
