The Digital Masquerade
Don't get seduced by the digital masquerade ball. It's a slippery slope. If you have more than a single digital persona (like I do), don't let one be your shield while using the other as a sword; don't go all Jekyll & Hyde.
For me, one persona is a remnant of a business venture—a scaled-back, primarily social voice dedicated to specific subject matter (soccer). I make no secret of the affiliation, but I use that persona for one thing and my other one for everything else. It's not without its challenges. It isn't always easy to be "myself" given the limitations (e.g. the difficulty of communicating clearly, explaining context, or being patient bursts of 140-or-less-characters). But I don't intentionally pretend to be something I'm not; and I don't say things that I, the actual person, wouldn't.
How do we check ourselves? "Think before you tweet!" has long been a mantra of mine. Check in with your digital self every so often to see how you appear when you're not in the moment. Try to limit yourself to one voice on one account. Listen more than you talk. Oh, and get offline! The more connected you stay to the real world the better equipped you'll be to navigate digital waters.
If you've ever struggled to reconcile your real and digital self, I recommend reading "I Am Not My Internet Personality, and You Probably Aren’t Yours, Either."