The discipline to write every day. It's easy to give yourself excuses and say, "I'm not inspired to write today" and put down your pen. But it takes a lot of discipline to tell yourself you need to write every single day, regardless of how you feel, motivated or not.
Then, when you start writing, the challenge is to get over your self-doubt, to quiet the voices inside of you saying things like: 'you're not good enough to write', 'you? a writer? don't kid yourself' and other things that put you down.
In short:
- the discipline to write regardless of how unmotivated you feel and
- the courage to write regardless of how lousy you feel