Holds true for almost any endeavor - playing an instrument, acquiring athletic skill or strength, overcoming/replacing a habit, learning homemaking skills, learning a language - you name it.
It's not new, been around forever. The personal discipline formula, then:
Consistency (do it regularly for at least 10 years:)
Frequency (depending on the skill: daily, eod, weekly, etc)
Duration (practice session has to be done long enough, varies with age & current abilities, could be 15 minutes to an hour or two daily)
Intensity (degree of effort, sweat and/or concentration)
Correct technique (does no good to practice if you're practicing it wrong)
Power. Strength. Skill. Freedom.
The ability to begin and stay with the above skill formula, well, that's really not so difficult if the motivation, the 'want-to' is there.
And when the motivation isn't always there, well, personal discipline still trumps all, I think. I have yet to meet an accomplished pianist who is sorry they ever learned to play the piano. I've met lots who wish they had stayed with it. Same with almost any endeavor. Ever met anyone who regrets running a marathon? Or heard anyone say, "I am so sorry I ever learned French?" Who regrets having skills, talent, knowledge? No. It's always those who don't play or don't have physical strength or don't develop a skill or don't speak a language who say they don't miss it and don't need it.
There's so many things that she wishes
She don't even know what she's missin'
And that's how she knows that she missed
--excerpt lyrics from Sandra by Barry Manilow
And how this post on discipline morphed into Barry Manilow lyrics is beyond me. But, anyway. I'm in favor of the big P.D. and wish I had more. Could also use a couple of extra doses of motivation, too. Still working on a formula for that.