According to Robert Genn, whose articles I often enjoy reading this question is answered as such:
Know that others have gone where you wish to go.
Put "getting good" ahead of "making a living."
Learn to be alone and to be your own best critic.
Cut back on impedimenta and outside distractions.
Work more hours than the average factory worker.
Notice interesting directions and go there again.
Become a perpetual student of your own progress.
Don't expect too much help from anyone or anything.
Stick to your vision, but don't fear change.
Do not be adverse to developing skills.
Know that raising standards has to be chronic.
Know that marketing is easier when you have quality.
Be curious about everything, including how you turn out.
If you fall in love, accept the gift, surrender.
PS: "When love and skill work together expect a masterpiece."
Source: Robert Genn Twice Weekly Letter [email@example.com]