Its the reason apps like Instagram exist- they allow you to polish your images so that you can basically tell the world, "hey look how much fun I'm having, and you're missing out"
Facebook/Twitter/ in fact a lot of these publishing platforms exist to weed out the mundane parts of your life so that what is public is the most exciting, jealousy inducing 'Cliffs Notes'.
Essentially, thanks to them, when you die, people will be able to look at your profile or your tweets and mourn, "that person lived such an interesting life."
Whatever you opine upon reading this is your answer to your question (as I see it)...
As uniclaude said blogging is a great way to get out to an audience in your related niche. Get those people to interact with you on twitter as well and you have a good group of people.
I would stay away from most things more than that. Social media can take a very quick turn from building an online influence to wasting your time reading random things.
If you're a developer, a few meaningful contributions on Github will be worth all the posts you can write on Facebook.