No matter how long you've been in this business, you can never stop learning. From your peers, your competitors, your coworkers. From formal courses to online tutorials. And if you're a designer, one name that comes to mind frequently is Aaron Draplin, designer and founder of Draplin Design Company. His work is admired and emulated by every designer I know. But what's best about him is his excitement and willingness to share his knowledge and experience.
If you have not joined Skillshare (https://www.skillshare.com/) yet, do it now and watch Aaron's video, Customizing Type with Draplin: Creating Wordmarks That Work. You'll be glad you did. He will do more than simply teach you new techniques and ideas, he will inspire you!