Note: For best results for creating an icon, you will need a graphic program that can save the image as a Windows ICO file. Thus, if you can create your own icon then you can use that icon on any shortcut. The icons of shortcuts can be changed to ones provided by Windows or ones provided by the user.
These shortcut icons make up the bulk of what displays on your Desktop and in the Task Bar so any customizations will be noticed and useable. The icons for folders and non-shortcut files can be changed, but that is a topic for different posting. The following instructions are how to create and use custom icons for your shortcuts. You can create such unique icons that you can easily find the icon for the application or file you want. I think customizing my icons makes it easier for me to tell the icons apart and find the icon I want faster.
Some users believe customizing their icons is a waste of time, but I disagree.