I think that the secret of art is divided in two: PASSION and DADICATION. Passion is when you're fond of something so much that you'd do it all of the time, Dedication is what you need to improve. If you have passion and art is what you really want to archive in your life then you will find yourself giving it all of your time and you might not even need to think about dedication cause you do it spontaneously!
But as soon as you grow up (I know what you're thinking eheh) you usually don't have enough TIME for it, it happened to me also! TIME's always the problem but I'll tell ya a secret: there's no busy day that can really take you away from doing what you love.
So make sure to have passion and dedication on anything you do and I promise that you'll improve at a glance!