I've had a lot of to-do lists in the last six months. I've tried a few major ways of looking at them (goals? single steps?) and all of them have failed to one degree or another. The ones that lasted the longest are:
I have a whiteboard sticker on the wall of my office, right above the lightswitch. I can write anything I like on it, so I used it as a place to store my big three goals (for the week, and then big three goals for each day) somewhere visible.
It worked well for several months, until I realized that for several weeks I had been writing goals that boiled down to "do your job." Writing other goals had the bad habit of being lower-priority than "do your job" and often failed.
This lasted a few weeks, largely because I am notoriously bad at actually checking lists. They're good for me for organizing my thoughts and for long-term reference ("stuff I want to buy for my home" with links), or immediate use ("let's make a grocery list, and then go and buy the things directly afterwards"), but if I need to actually remember to check my to-do list I will generally rely on my less-than-reliable memory.
What's working now?
So far I've been having good success with actual, physical sticky notes. I choose three things every morning when I boot up my computer for work, write them on separate notes, and I tell myself that I can't leave work 'til all three have been put in the garbage. Generally they're pretty easy things, but I am consciously avoiding doing things like "X number of emails done" (working a support role lends itself to that sort of metric). Even if most of my day is spent on emails, I want to ensure that my additional projects - which serve to improve the company, my team, and sometimes even the software we support - are given priority in those three post-it notes.
Speaking of which, I have one left in front of my monitor, so I should probably wrap up my lunch soon and get back to it.