By definition, an icon is a graphical representation of an action, idea, or object. Its main goal is to deliver a message. When chosen on a whim, icons can confuse users and prevent them from accomplishing a task.

How can you use icons without the potential risk of causing unnecessary cognitive load?

• Stick to universal icons. Universal icons, such as a floppy disk for saving or a house for returning to the home page, are a safe bet. They're universally recognized and don't require mental processing.
• Accompany icons with labels. Universal icons are the best, but they don't cover all possible actions. Using unique icons together with labels eliminates ambiguity and clearly communicates their meaning.

If it takes longer than 5 seconds to think of an icon for action, the icon won't pass the recognizability test. Even worse, it may lead to confusion and increase the cognitive load.