Platform takes time and development. It equates to how wide your circle of influence is—or how many books you can sell. There are tons of great articles out there on platform, so I'll leave it to them. I want to talk about voice and brands.
So, don't try to brand yourself until you've got a few completed manuscripts or even published books. Then talk to your crit partners about their commonality.
Ane Mulligan writes Southern-fried fiction served with a tall, sweet iced tea. She's a novelist, a humor columnist, and a multi-published playwright. President of the award-winning literary site, Novel Rocket, she resides in Sugar Hill, GA, with her artist husband, their chef son, and two dogs of Biblical proportion. Her debut book, Chapel Springs Revival, released Sept, 2014. "With a friend like Claire, you need a gurney, a mop, and a guardian angel." Following will be Chapel Springs Survival, Oct 2015, Home to Chapel Springs, May 2016. You can find Ane at her website, Novel Rocket, Facebook, Twitter, Pinterest, and Google+