There's a great presentation on the topic by Angelina Fabbro www.youtube.com/watch?v=v0TFmdO4ZP0 with matching slides http://afabbro.github.io/jsconf2013 . The title says javascript, but it's really a platform agnostic guide that sketches out what mastery looks like and lays out actionable steps to get there.

Seriously, listen to the talk and/or check out the slides.

But 90% won't, so here's her actionable steps:

  1. Ask why obsessively
  2. Teach and/or speak at an event
  3. Work through a suggested curriculum*
  4. Experiment recklessly (the code doesn't care)
  5. Have opinions
  6. Seek mentorship
  7. Program a lot
  8. Stop fucking programming sometimes.
  9. Write Javascript* a lot
  10. Write in another language for a while
  11. Think like a programmer when afk
  12. Know what feedback is good feedback and reject everything else.
  13. Break free of imposter syndrome

* These are the two points you'll need to adapt to your choice of language