This article in Elle Magazine by Charlotte Cho captures the fundamentals of having a great personal brand. One thing I would add to it is that Your Brand is the intersection of all the things you do to support what you want people to think of you as, and what they actually think of you.
Recap of key points:
- Do work that excites you
- Be yourself
- Give give give
- Gather Praise
- Make sure your brand is consistent
Pick visual elements & language that fits 1-5.