Write commercial music that offers music consumers something they have not heard before. Put your unique spin on the genre you belong to. For example, if you play country music, you could incorporate some alternative rock elements to stand out.
Record your music in a professional manner. While it is possible that a record label will show interest and sign you based off a rough recording or a cheaply made video, you will have a better chance presenting your music in a professional format. Record demos of your songs at a professional studio or with a recording engineer who can turn out a master-quality recording. If your thing is videos, record with a quality camera.
Establish a presence on the Internet. Create a profile at a music promotion website like Bandcamp or PureVolume. Post your videos on YouTube or blip.tv. Record labels sometimes discover musical artists searching sites like these. It is also a good idea to have a strong web presence if you get in contact with a record label regardless.
Promote your music and build up your fan base. Create a buzz by posting links to your music on forums, buying ad space on music websites and playing live shows. Record labels are more likely to listen to your music if they see you have already done a good deal of legwork and have some commercial potential. Make them come to you.
Submit your music in a professional press kit to record labels, including a three-song demo, cover letter, biography, photo, press clippings and other pertinent information. Be sure to follow the instructions set forth by each label. For example, some labels might request a four-song demo or might not accept unsolicited demos.