The following is a very basic but also quick and accurate way to sharpen your images, again it starts with duplicating your layer in case of mistakes. This seems like the next logical step after removing dust and scratches as you can sharpen a whole image as opposed to the previously mentioned method of sharpening only certain areas.
Once duplicated you follow the menu - filter, other, high pass and order the pixel radius in order to determine how much of the image will sharpen. The image is shown in greytones and is then revived by altering the top layers representation from normal to any choice of light between overlay/soft light to vivid/hard light. As before sections of the new layer can be erased in order to show original parts of the image where necessary.
Again this is a very quick process and paired with the previous one can lead to clean, dust free images that retain their original sharpness.
