When you provide feedback to others on their work as opposed to only reviewing your own, you begin to see things from a different perspective. Giving feedback on your peers’ work gives you an insight into what works and what doesn’t work and how you can come up with something even better. It inspires you and broadens your ideas. By taking the time to identify what appeals to you (or why it doesn’t), you’re teaching yourself and can, therefore, apply it to your work.
On the other hand, when others critique your work, the information they provide you with may surprise you as well. After having experience with giving and receiving feedback, I’ve learned that this tactic gives you a well-rounded view of your work and enables you to tweak your efforts in a way you maybe couldn’t before. It’s a great learning experience and something everybody should consider practicing more often.