Dancers are forever trying to improve their turnout, but according to this orthopedic surgeon, who was interviewed by Dance Magazine in "The Dancer's Hip", degree of turnout is determined by the architecture of your hip and there isn't much you can do to improve it. The surgeon warns against forcing turnout, especially for dancers with hypermobile joints who are very flexible. These dancers are very prone to tears, damage within the hip joint and can even slip the hip out of joint if turnout is forced.
So, what if your turnout is not naturally "good?" Not to worry - there are famous ballerinas who were known for bad turnout and still had great success. Ballerinas like Anna Pavlova, who is considered one of the greatest dancers of all time as a principal dancer for the Imperial Russian Ballet. There are plenty of other qualities besides turnout that make a dancer great - artistry, grace, strength, passion, flexibility, perseverance and ambition. Focus on the qualities that naturally set you apart and strengthen those rather than worrying about the qualities you can't change.
Click here to read the article in its entirety: http://dancemagazine.com/issues/January-2011/On-Dance-Injuries-The-Dancers-Hip