A few more miscellaneous thoughts. These are just personal preferences of mine—I don't know if they will help you sell more copies, but this is what I like to see on an album cover:

1. The title of the album (if it has one) should be somehow easy to distinguish from the name of your band. I am always annoyed, in a record store, when I pick up a CD by a band I have never heard of, and find that I can't tell which is which! (This may not be a problem if you only sell at gigs, but you never know.)
2. There should be some description of what type of music you play. Even a vague not-quite-accurate classification is better than nothing. It's amazing how many CD's are made with NO indication of what type of music it is. Jazz, classical, rock? I guess they assume you're already familiar with the band before you even consider buying the CD, but this isn't always the case.
3. It should identify what kind of instruments you play, especially if you play something unusual. Some people will buy all the CD's they can find that feature a certain unusual instrument. One way to do this is to show a picture of all your instruments. It could also solve the problem of what kind of graphics to use.
4. It should list all your cuts, by title, and indicate whether each one is traditional, original, or written by someone else. If traditional, it should indicate what ethnic type: Irish, American, Cajun, etc. (unless all the cuts are the same—then the info can go in the heading—see item #2). It should also indicate whether it is a song or a tune. (Some people favor one more than the other.)
5. Be sure it tells how to contact you.
6. Timing is not important to me, but it seems to be important to some people. Radio stations want to know the length of each cut, and some customers want to know the total length of the album. (It amazes me, but I have known people to ask.)
7. PROOFREAD! PROOFREAD! PROOFREAD! Then give your copy to the most critical anal-retentive person you know and have them proofread it for you. But don't expect them to be familiar with the spelling of every personal name, every place name, and every foreign word. Look these up yourself.