Tips To Be A More Interesting Person
(And have a more interesting life while you're at it)
Probably the most important thing you can do is to start broadening your knowledgebase. "Interesting" is subjective; different people find different topics interesting. The more you know, the more you'll have to talk about with other people. The more you have to talk about, the more likely you'll be able to engage someone in a conversation they'll be interested in. You don't need to have expert knowledge about a subject, but of course the more you know about a given subject the more you'll have to say about it if someone does find it interesting.
Try new things. This cannot be stressed enough. Listen to music genres you've never listened to before. Try new foods. Give new activities a shot. Read/watch new things, especially outside of your typically-preferred genres. You'll make yourself look more adventurous (and therefore more exciting) - and even if you don't end up liking what you try, you'll at least be able to form an opinion on it. Remember, people without opinions are boring. (Also, see How To Be A Good Anti-Fan.)
When it comes to talking about your personal interests, be careful that you avoid sounding like a fanatic - this can put people off, especially if they don't feel as positively about it as you. If you sound like you won't be content until you've convinced your target that whatever you're talking about is the Greatest Thing Ever, you're probably going to push your target away. Remember, you're not there to convert new fans; you're there to have a conversation. (For dealing with people who strongly dislike something you're a fan of, see How To Deal With Anti-Fans. And whatever you do, don't be a revolting fan.)
Also, pay attention to your target when you're talking - if they start looking away from you, fidget, start 'spacing out,' or start talking about another subject, that means it's time to try talking about something else - or just start listening to your target. (No matter how 'interesting' you are, people are going to be turned off if they can't get a word in edgewise.)
It helps immensely to stand out in some way, whether it's through a unique perspective, attitude, sense of style, figures of speech - anything, really, so long as it stands out. Basically, you need to offer something that few, if any others offer. In that regard, it doesn't hurt to have a skill that's entertaining or useful, either.
You can also take inspiration from people and even characters you find interesting and incorporate some of their aspects into yourself - but be careful: if it's obvious that your new "interesting" persona or aspect was lifted from a specific character or person, more people will be put off by you than drawn to you. People admire those who are perceived as original; those who are perceived as copycats, sycophants, or "posers" are derided. Remember, there's a difference between taking inspiration from something and copying it - EG, learning to tell jokes because a character you think is interesting tells jokes is taking inspiration; telling the character's actual jokes is copying.
One very important thing to remember - if it's obvious that you're just doing whatever it is you're doing to get attention, or are being different just for the sake of being different, it's probably going to backfire. Neither are people going to appreciate your "uniqueness" if you're disruptive or obstructive.
If you think of your life as "boring," stop right now. It's not about what happens in your life so much as how you look at it. Comedians such as Gabriel Iglesias and bloggers like Allie Brosh and any number of anonymous rage comic makers get people laughing over personal anecdotes that are no more unique or exceptional than anyone else's lives - what makes it seem special and exciting is how it's told. Keep your eyes open for the little things that could sound absolutely amazing or hilarious if you told them right.
Finally, work on improving your wit. See Basic Tips To Be Witty & Funny for more on this.
And one final note - a cool side effect of being an interesting person is that you're more likely to have an interesting life! :D