Personal branding requires orchestrating how you are represented in various online platforms, including social media, blogs and forums, a personal website, and any other platform that projects information about you. I argue that you should take a “bottom up” approach with your branding; this means you plan how your identity (profile, content, etc.) is projected onto networks, rather than a “top down” approach where you start with the network and then manage your identity (often times a reaction).
There are many tools to help you manage your content and profiles based on what is already out on the public domain and without question, you will have to manage them. You probably already have a Facebook and LinkedIn profile. Nevertheless, I think you should conceptualize how you are represented with these services and all other services you subscribe to based on how it promotes your brand. Find out how to utilize the key features of each service and leverage them to promote your personal brand – a representation of your skill set, how people perceive you, and an identity.
You should proactively build your personal brand. There are times when you will have to react to what someone says about you and how it might impact other people’s perception of you, however make this an exception; whenever possible take the reigns of your personal brand. Be proactive rather than reactive.