That's at the macro level. On the micro level, structure helps a lot. Some of the more go-getter people you know are just on autopilot, but have done the work beforehand to hack their motivation, mostly by forming habits and setting themselves in social environs that reward achievement.
Motivation is a fickle, mercurial beast. Trying to run on it at all times won't work. Use motivation wisely, for short bursts of work that get/keep autopilot-you on track. Things like: going to sleep when you want to stay up, making a plan for issues you don't want to think about, setting habits to do things you don't like to do.
Forming habits and getting to the point of autopilot is how it happens for me. At some point you don't even notice it because you are so focused. It's just like getting up to go swim every morning. It's cold as hell and you don't feel like it, but you know that after 10 minutes in, you will feel great. And then you just get into the routine.
The last part by dropit_sphere is a particularly good thing to understand about oneself. Can't have it all the time and you gotta use it efficiently when you do.
Kudos on recognising the prevalence of this phenomenon. When people are running in a reactionary mode, trying to reprogram the system is asking for failure. Just like with a black-box program, the input parameters need to be changed if you want the output to change. Your environment (including objects, TODO lists, people, emails, texts, location, food, and drugs) constitutes the input parameters. The environment must be changed for the output to change. If you forget to change your environment after recognising a problem with the output, then you fail to make a lasting change in the system. Essentially, your environment is a part of the extended you that you can pretty easily "reprogram".
That sounds like an interesting approach to life: Improve your environment; watch yourself improve; then repeat. It's like a big optimisation problem slowly working its way toward the maximum. It's like a personal singularity.
Sometimes I spend so much time in my head that I forget to change my environment. It would be nice if our best thoughts could somehow be put into effect more quickly without necessarily interrupting other planned activities. I guess that's where self-control and sequential execution come in. At the same time, the original plans may have become invalid.
Sometimes after you change your environment, it's like you have to re-compile the kernel before you can run the program you were initially planning to run. The trick is in not losing state information during that recompiling process. Sometimes writing cookies (aka, notes) can help here. Conversely, some changes are so big (or time-consuming) that your whole plan needs to be re-wired.
They say that teaching is one of the best ways to learn. My experience seems to confirm this advice. Perhaps when you go and explain something to someone else, not only do you organise and solidify the understanding in your own mind, but since you pull something out of your brain and stick it to the extended you (and beyond), that knowledge can take on a life of its own in the outer world. Your very awareness that the knowledge has been transmitted to the outer world seems to have a strengthening effect in your "inner you". It's as if the outer "awareness" links back to hidden parts of the inner you, as were it virtual dendrites connecting your brain to the collective consciousness.
So I say to myself just pick something and do it. The reward is the gratification of crossing it out. If a sheet gets filled up, I transcribe the remaining items to a new page, which engages visual, verbal and kinesthetic learning modes and refreshes my perspective on where I'm at with the project.
There is most always a space to the right of my mouse for the current pad. The system breaks down when that space gets cluttered for whatever reason. But when it's there I jot down tasks that come up while I'm coding. I keep the pads organized in a flat file that is just big enough to hold papers.
It works for me. Also getting enough sleep, exercise and eating properly helps.
The target is flow, the enthusiastic engagement in that activity I so desire to be motivated to do.