Keep "You" (AKA Your Picture) Consistent
Keeping your profile picture consistent across channels makes its 10,000,000x (this has been scientifically proven) easier for people to find you. Make sure it's a headshot where you are actually visible in all formats - think about how it will look on a phone screen, a Twitter stream, a newsfeed etc. Another thing to note, don't change your picture every week - it's hard to keep track of! Think of your picture like your logo, if all of a sudden, Ralph Lauren started using a lobster instead of a pony - wouldn't it annoy and confuse you?
Write Bios
I know it can be tedious, but try to write bios on all your platforms, even if they are only a hundred words. Yes, Instagram and Foursquare deserve them too. It can be short and sweet, simply stating your general life status, likes, dislikes etc. The great thing about it is, once it's done, it's done - unless you have a major life change, and even then you don't have to update immediately. This helps when people are trying to identify you.
Listen (Meaning... Respond, or at Least Interact)
There are people you love to follow on Twitter/Facebook/Instagram etc, so let them know it. As a community manager myself, interaction is our bread and butter. As a person, let's be honest, we all just love when people acknowledge that picture of our awesome new bracelet or our dinners out on the town. Comment, liking, retweeting, sharing etc, is how we acknowledge our social media community.
Censor Yourself (No, Not Talking About Cursing)
We have all heard it before, but don't post every little thing that goes on in your life. As the teacher in the hilarious movie, Easy A said, "I don't know what your generation's fascination is with documenting your every thought... but I can assure you, they're not all diamonds." Roman is having an OK day, and bought a Coke Zero at the gas station. Raise the roof." Who gives a rat's ass?" - Fellow inhabitants of the digital generation - let's not prove him correct.
Make a Home Base (A Personal Website Is Easy!)
Setting up a personal website can take just a few minutes, and many programs now make it almost completely painless. Sites like About.me (Flavors.me and claimed.com are good too) allow you to connect all your digital presences into one easy, shareable site, plus most are free (bonus!). I've listed a few below to help you get started, mine took be about 15 minutes to create (and even let me aggregate my Instagram photos as my background). Once completed, through the link into those bios (see #2) and you're done.