Four tips for starters:

• Make sure the CD production reflects your live performance (i.e if you are a duo, don't have a band playing on the CD)
  
• Include a list of your past performances
  
• Include any references from artists who HAVE played at the venue
  
• It is hard (and expensive) if you are located a distance from the venue, but TRY and get there to do a spot. If it WOWS the audience and organisers, you are half way there!