It is a widely accepted concept in people photography and wildlife photography that getting the eyes of the subject sharp will make or break a photo.  One obvious exception being abstract photography.  In can be pretty tough to gauge sharpness on macro critters, and it is not easily achieved in outdoors field photography.  By my estimations, I take at least one dozen shots of each composition while looking through the viewfinder and being thoughtful of my shutter speed to get the photo I am after.

A magnified view to aid in image sharpness checking. RAW preview on left and optimized JPEG on right.

A composite image shows one of the few frames that met my sharpness standard for this capture of an Orbweaver spider.  It is not blurry before processing and it is not blurry after processing.  The main changes are contrast enhancement along with light noise reduction and global sharpening.

An outdoors spider in New Jersey, photographed handheld with the Tamron SP 90mm VC and the Canon EOS 60D.

Above we see the full view of my macro photo in its native 3:2 aspect ratio with no cropping performed.  Using my 60D and Tamron 90mm VC, I manually exposed with settings of 1/100th F/4.0 ISO 200.