Listen to educational podcasts on your commute.
Sign up for a few good email newsletters to score some extra factoids for casual conversation.
Whenever people are talking about the economy, just say, “It was all downhill after they repealed Glass-Steagall.”
When someone asks you the last good book you read, just say “I can barely keep up with the New Yorker!”
On that note, have a favorite writer, book and artist ready to name drop.
Pick one or two longform essays to read each week.
Learn one new word a day and try to use it (naturally!) in conversation.
Refer to an NPR personality by his or her first name only.
Don't assume wearing glasses makes you seem smarter.
Hang out with people who are... less smart.
Write emails with proper punctuation and capitalization.
Become knowledgeable about one random thing.
Be confident! You probably seem pretty smart by now!