Communicate via social media
Like it or not, social media is now one of the most important tools artists use to build buzz, promote their work, and interact with fans. Having a strong and consistent personality on Twitter, Instagram, and Facebook is more important than ever. So, post things that you want fans/onlookers to know about you in a way that makes sense with your personality and music. But please do not try to go viral by tweeting the link to your mixtape to everyone you know.
Different methods work for different artists. Lil B tweets obsessively and follows over a million people while Kanye tweets every few weeks and only follows one person. Social media is as close as you can physically get to introducing yourself to everyone who might take interest in you. Don't take that lightly.