For me, it's to-do lists and a work ethic based around finishing once the task is complete, not when the clock says it is time; and a real passion. If you look at the sites I am a member on here, you can very easily see the handful of sites I have a passion for, and then those I am vaguely interested in. With passion for a topic, you can be inspired to self motivation, delivery, detail and effort...Without passion, it is just effort.
Like @Gilles, I fit my SE time in around my various work tasks - SE for me does not give me anything other than satisfaction at seeing things improve (I do a lot of mentoring and coaching in and around my day job and it does make me feel useful when I can help others understand a topic)
I head up a couple of professional bodies - for those my to-do lists are all on electronic shared docs, so as committees we are accountable to each other.
In my main day job, I mostly use paper lists, as there are so many projects, tasks, management items and team members that electronic lists get too unwieldy very quickly (and I am of a generation that grew up with pencil and paper, not iPads)
And for my family, I have a calendar showing which sports competitions they are attending so I know where/when I need to be somewhere.