Even if you aren’t a professional icon designer, you can still customize icons with your own creations. In most cases, all you need are the graphics programs you already have on your Mac.

In iPhoto, select the thumbnail of the picture you want to use as an icon, then right-click and select Copy. In the Finder, select the item with an icon you want to replace, then right-click and choose Get Info. Click the old icon in the Get Info screen, press Command-V to paste your picture, and you’re done. For better results, duplicate the picture in iPhoto, crop it constrained as a square to highlight a face or other cool detail, then paste that image over the old icon.

She’s ready for her Desktop closeup.

If you have an image editor like Pixelmator or Photoshop, you can create your own icons from scratch. Create a new document at a file size of 512x512 and a resolution of 72ppi, then draw your design. When it’s complete, copy it from the document window, then paste it into the Get Info window.

Be honest, which icon would you rather click?

But sometimes pasting doesn’t work. You may need to create an ICNS file to copy into the Resource folder of a stubborn application that won’t otherwise accept a new icon. A utility like Img2icns ($12.90, img2icnsapp.com) can create the necessary file from your custom image, and the trial version even does it for free.