Interesting topic. Changing habits is so important and yet so hard.
I think reminders are key.
For instance, I still haven't mastered my GTD flow. I sometimes find an idea pop into my head, then I'll pursue that idea, only to find 1/2 an hour has gone by, when I should have just put a NA on my task list in the first place. So now I've setup an outlook appointment "Look at NA lists". I snooze it for 15 minutes when it pops up. So basically I have a reminder every 15 minutes that I should be working on my NA lists, rather than what pops into my head at the time.
I'm sure you could use another reminder/scheduling software to do something similar.
The Seinfeld calendar marking has also helped. It reminds me that I have to do something that day, or I don't get a pretty red X.
Just some thoughts,
Quick thought: "Ideas that pop into your head" belong in Someday/Maybe, in my opinion.
It is so true, one needs regular reminders, maybe more so NAs. I realized I also need to learn more on changing habits. Coincidentally I came across this article 18 Tricks to Make New Habits Stick . I came across this site from a post in here, so I think it's ok to link to it.