I think art is a lot about learning from mistakes 🙂 I ran a beading workshop and showed some things I'd made that were FAIL GRADES, and I explained why.  I then held up another piece and someone said "too busy" ... I said "that was supposed to be a success story" LOL.  

One of the nice things about art is that judgement is subjective in most cases ... what one person likes, another might hate.  There is no "right answer" like in maths.