It is important to have some type of sound treatment panels that will diffuse bass and reduce any echo. You basically want the room to be flat. This will give you a true mix of your music. If you mix a song in a room with no treatment, the bass may sound heavier than it should be thus you will mix it with less bass. Then when you play the final mix somewhere else, it sounds like crap. Here is a video that shows how to make some panels for about $100. Which is not too bad considering that stuff is expensive.
Artists and bands be sure to submit your music at these radio networks.
www.hardcorejamz.com (Playing Hip-Hop and R&B)
www.hardcoremix.com (Rock,Pop,Country,Jazz,Electro,Gospel and more)
Submit music on either site.