I was recently asked by a casual darter as I picked up several sets of my darts from the post office "what does it take to get good enough to hit what you want?"
My answer was "time".
Her reply was "time? as in take your time when you throw?"
I answered: No, but rather time on the board.
You see, while everyone is different I think time is the real difference in making an accurate dart player. It takes a lot of time just hitting the board over and over again to develop your throw. So take the time, hit the board often, then hit it more and more and more. Wear the board out, get a new board and do it again and again.
In time, you will develop your throw and accuracy but don't get discourage too early. Some, like me, have spent more time throwing darts than others have spent working!
Play often, practice more, and let time do it's thing.