#1 Have books handy
Not just any books, it has to be particular ones. Having each Twilight book on your shelf isn't going to do you all that good with the type of people we're trying to attract. So what books do you need? There's a lot of options and it shouldn't be too difficult to decide what will work and what won't. Just ask yourself "Would a smart person read this?" or in other words "Is this book beyond me?" If it is, you've got something good! It can be anything dealing with literature (the study of/ and or classic novels) mathematics, science, or some other genus reading material. Now what you do with those books is important. If you ever have people coming to your home you want to appear smart to, have these books handy. They can be on the bookshelf or even on the coffee table. Try not to make it too obvious that you want them to be seen. Throw a couple of average readers on a shelf next to them. Even a couple of well selected books can do the trick.
Here's my own example. Look at these books. There is no way of knowing if I've actually read them or not.
As far as any passerby is concerned, I have. But the truth? I'm yet to read Literature and Life in America. Love Poems and Sonnets of Shakespeare I'm rather afraid to read. Industrial Control Instruments I have never read and never will. The only reason I got that book from a Library sale was just for this purpose! For show!
But not everyone you want to come across as smart will be in your home. This leads to #2, which is similar to #1.
#2 Carry a book around
All the books you have reserved for #1 will work for this step. You don't have to carry a book around with you where ever you are, just in appropriate places. That's really for you to decide.
Don't pick the MOST difficult book to carry because you should be able to read it if you absolutely have to in an emergency. I'm not going to carry that Industrial Control Instruments book around. That would just be silly. Take a book that interests you, but you probably won't be reading its entirety any time soon.
This is an example that's already worked for me. I did state testing this past year for school and in between sections of the test we were allowed to read. As one teacher past by me she asked what I was reading. Wordlessly, I showed her this page. Yes, it was the autobiography of Italian metal worker Benvenuto Cellini. Her only reply was "Oh...that's deep." I had only read two pages of this book and that's all it took. The teacher had much more to say to the girl next to me reading The Hunger Games. Ha! It takes a certain kind of person to understand the things you and I will be holding. Harvard classics only!!!
#3 Watch T.V and YouTube
You're probably already doing this step. You can pick up bits and pieces of information with this. Not everything you watch will be useful. Obviously you will learn more from a documentary than you will from an episode of Keeping Up With the Kardashians. But what's mentioned by the people in shows, movies, and even videos on the internet can teach you something. It's not going to teach you anything in depth, but it may be good enough. You've probably heard of people knowing "a little bit about everything." Well that can now be you, all from you paying attention to your entertainment! You can benefit from this by dropping these bits on information of what you know in conversation when applicable.
#4 Quote exoteric movie lines
When the discussion turns to film, you can quote exoteric lines from movies (well known and obscure). You don't have to claim whether you've seen the movie or not. People will be blown away from you reciting an excerpt from a movie. They will be so awestruck that you won't even need to say anything else for the rest of the conversation. That may be because you don't know anything about the movie, but they will probably assume you just know it so well you're above talking about it. A few times I've quoted "“What is the victory of a cat on a hot tin roof? I wish I knew... just staying on it, I guess, as long as she can...” Have I seen the movie Cat on a Hot Tin Roof? No. But you would think I did if you heard me quote it.
In case of an emergency mention the sled that said "Rosebud".
By following these steps and whatever else you can think of- you can successfully appear smart, knowledgeable and interesting. You may have very shallow friends but take it for what it's worth.