Re: Sharpening Techniques
So they are referring to getting sharper photos in the camera? This comes down to using proper technique. Using a tripod will help, a lens with IS will help if used properly, using proper long lens techniques to reduce camera shake, mirror lock up, choosing the sharpest aperture for your lens will all help to get sharper images at the point of capture. Without reading the article it's hard to say exactly what they are referring to.
Re: Sharpening Techniques
There is software which can make images appear sharper. But it's much better to get a sharp image out of the camera than mess with images after. To get the sharp images, requires basic knowledge of exposure and physics of optics. The depth of field effects is confused with sharpness when telephoto lenses are used and the poor photos taken with a good lens with a slow shutter speed with a telephoto lens, hand held.
I just listed a few problems that can bite you in the behind if you don't understand exposure and basic optics.