If I struggle with procrastination for shorter periods of time or for specific types of chores, I'll use productivity techniques like a pomodoro timer, rewards, etc. And like others have said, breaking down large nebulous tasks into smaller more well-defined ones and making a daily todo list at the beginning of each day is important (the latter is one of the only 'techniques' that I've found to be consistently useful for me over a long period of time)
But if you struggle with procrastination and demotivation for months on end, I think you need to think more about what motivates you to work in general, apart from needing to put bread on the table. Two key questions to ask is why you do what you do (the vision), and the circumstances under which you do it (your everyday work). Either of these can motivate you - ideally you'd be motivated by both (doing tasks you enjoy, which also meaningfully moves you toward fulfilling your vision) but you might also be ok with just one or the other (e.g. you might but up with slogging through chores for a while if it helps you achieve your bigger vision, or you might put up with a 'visionless' company for a while in order to play with some cool tech). But if you get neither, then there's a high chance your motivation will go over a cliff - it sounds to me like this might be the case for you.
Here are some things to consider in terms of how important they are to motivate you, at the vision level:
- How many people does the work impact?
- How important is it to them if it is done well?
- How 'altruistic' is the work? (do you feel like the world becomes a 'better place' from it?)
- How important is it for you if you own the company yourself or someone else does?
- How important is the 'prestige' of the job for you?
- What kinds of 'achievements' would you be motivated to pursue? (e.g. speaking at a conference, making a name for yourself in your field or similar)
And at a daily level:
- What kinds of tasks do you enjoy doing (e.g. for me as a programmer, user-facing features are much more fun than backend tasks)
- How much do you want to interact with end users/customers/clients?
- How much do you want to interact with colleagues? (everyone needs some amount of social interaction and it can get lonely as a freelancer)
- How much would you like to be doing tasks yourself, and to which extent would you be ok with/prefer to just oversee others doing the tasks (some people prefer being hands-on and focus on just a few tasks at a time while others prefer to be a manager for many people, so you don't go as deep yourself, but get to have a hand in everything)
- What other things can motivate you about your daily work or work environment? (e.g. a good cafeteria, short commute, flexible hours, etc.)
The balance of how important each of these aspects are vary from person to person, and for a person over time. For example I was working at a game engine company and while I loved the vision (that I could help thousands of creative people turn their ideas onto reality) and the colleagues (places with great visions tend to attract really cool people) and while it was initially a fun challenge to get the hang of C++, I eventually got tired of the cruft of a legacy codebase, and probably most importantly, I felt like I was wasting my most productive years realizing someone else's dream instead of building up a company of my own, like I'd been dreaming of. I was lucky enough to find a co-founder just at the right time, because I also know about myself that I tend to get demotivated if I'm not interacting with other people daily.
Anyways, the point is, 'fighting down' procrastination is a necessary skill sometimes, but sometimes you also just have to listen to what your subconscious is telling you about what motivates you and find something that does. It's important every once in a while to look at both if you're going somewhere you want to go, and if the path that you're taking there is one you care to walk on. There's no shame in realizing that something that used to motivate you doesn't anymore, or something else has become more important to you now. People grow, and boredom and dissatisfaction is part of what drives us to do so.