After Favorites have been added to the home screen, you can add custom artwork to make them really pop. Custom artwork should be 1920 x 1080 in size, and a number of user-created images can be found here.
Step 1. To add artwork for a Favorite, long-press on it and choose the Select Artwork option.
Step 2. You can now browse for the artwork you wish to use, and preview how it will appear on the Favorite icon.
Step 7. Your selected artwork will now appear in place of the standard Favorite icon!