I use custom icons on our school computers instead of the standard Mac icons. This helps students find the link or shortcut I want them to access more quickly and easily, and it only takes a few minutes to do.
To begin, download the image that you want to use for your custom icon. I like to search for what I want on iconarchive.com because they have thousands of free, licensed images. You can use either a .jpg or a .png format, and it should be at least 48 x 48 pixels in size.
Double click the image you downloaded. It will open in Preview. Choose Edit > Select All (or use the keyboard shortcut Command + a). You will see the outline to show it has been selected.
Copy the image (Edit > Copy or Command + c).
On your desktop, click the icon whose look you want to change. Make sure you click it once to select it, not twice to open it. Then go to File > Get info (Command + i) and click the icon preview at the top.
The blue outline that appears shows you that the icon image has been selected.
Paste the image you just copied in its place (Edit > Paste or Command + v). If you like, you can change the name appearing under the icon as well by editing the Name & Extension section.
Close the window and you are done!
