Learning CSS animations by working on animating popular icons can be an excellent approach for several reasons. Firstly, it provides practical experience applying animation techniques to recognizable forms, enhancing your skills in a way that feels rewarding and relevant. These icons often have simple, clean designs that make them ideal for beginners to experiment with, involving familiar elements like rotations, scaling, fading, or transforming positions.

Additionally, by animating existing icons, you can focus on improving your understanding of CSS properties like ‘transform,’ ‘transition,’ and ‘keyframes’ without getting bogged down in complex design work. You also gain insight into the subtlety required to make animations effective—not just technically proficient but also aesthetically pleasing and communicative.

Animating popular icons can also introduce you to more advanced concepts, such as coordinating multiple animations for various elements or ensuring animations run smoothly across different devices and browsers, further elevating your knowledge of responsive design and cross-browser compatibility.

Furthermore, this technique can serve as a motivational tool; seeing a familiar icon come to life through your efforts can be immensely satisfying and validating, keeping your learning momentum high. You could even apply this practice to contribute to open-source projects, giving back to the community while solidifying your skills.

To get started, select a set of popular icons you like or frequently use. Then, explore CSS animations uniquely suited to each—perhaps a slow bounce for a mail icon to catch attention or a gentle spin for a loading icon. As you grow more confident, explore frameworks and libraries that can optimize and enhance your animations. This hands-on approach not only hones your technical skills but also ensures you develop a personal style and understanding of behavior and flow in web interfaces.