If you play a particular style or instrument or kind of music try to convey that visually. Someone working in a record store should be able to look at the cover and know what section to put your CD in. Your title can also reveal a lot about the music. From the description of the cover and the title you probably know what the music sounds like. Try to think about what makes you unique as a performer or group.
Some labels use cut lines after the groups name and the album title.
USA label Music of the World always uses a cut line on their covers to specify what the music is and where it is from. Their titles will never be mis-filed in the stores. Remember to make things simple for retailers. It's vitally important that your CD has a catalogue number on its spine. These are the numbers all major stores use to keep track of their inventory.