Apart from Knowledge(this can not be avoided), few more essentials I feel,
Do Pet Projects based on your learning. Keep your GitHub crowded with repositories reflect learning by doing small projects. The greater advantage is, you go back to those anytime and improve as you learn more. Also, it helps you to have a mention in your resume about those.
Try Internship in a firm provides opportunity to work on a front-end project for 3-6 months. It gives lots of real-life learning with the opportunity to see how different the work-world is.
Be smart about selecting your courses, hands-on learning training etc. These are important and must to do but don't burn yourself by following ones may not of great help.
Last but not the least, try to be in touch with the folks aware of your potential as a front-end engineer and may get you the information on what is happening in the world.
All the best!