While I'm not exactly sure what "solo dev" means for the author in terms of intent, I believe that the need to manage motivation is usually a sign that what one is doing is at least somewhat off-course from the ideal of the individual. In simpler terms, if you are struggling to be motivated for something, you can certainly try to change yourself, but it can be at least as reasonable to change that something.

I learned this about myself a few years ago when I quit my job to build a compact piece of wearable hardware that measures metabolism through breath in real time. Even though I was burning through my savings, I spent close to a year working on this thing day in and day out. I had so many different "responsibilities" on my project and so many things to learn that motivation was never an issue, and I did finish a working device in the end. This is coming from someone who has dealt with motivational issues many times. That also wasn't the first time I quit my job to work on a project, though previous projects often ended early when I lost the motivation. At first, I thought this was a sign of a problem with myself, but in retrospect I think it's good that I lost motivation. Those ideas weren't that great and I wasn't as engaged in them, and it's likely I just would have wasted more time and money on them had I not acknowledged the writing on the wall.

In fairness, this outlook is easy to have when you aren't doing something for income. To some extent, we do have to manage motivation for day jobs. I can't honestly say that I'd be coding enterprise applications if I wasn't getting paid handsomely to do that. Even though I am paid, part of motivation is having a mission that's important to you, and it's easy to lose sight of your mission if you've been paid a regular salary for quite some time.

The author's "leave tasks unfinished" strategy plays into this principle at a very small level, but I think recognizing a greater ambition and keeping it in your consciousness can be important as well. A lot of people find the motivation to work harder and longer when they have kids, for instance. Since I don't have kids, I've found that regularly coming back to investing and retirement planning has been a good motivator for my day job because I get enjoyment out of making my money work for me; I loosely visualize what I want my life to be like in 20 years from now and strategize how to get there based on my current trajectory. I don't think about it most days, but revisiting this every few weeks reminds me why my day job is important. For others, perhaps owning a house and converting the garage to an art studio would be a goal to motivate one through their day job.

In short, I think motivation is more a form of measure than a virtue in and of itself. It can tell you whether you've lost sight of ambition or if what you're doing just isn't that great. "Hacks" will only get you so far.

That said, a "hack" that works for me is to just keep reminding myself to "keep up the pace." Even if I barely accomplish anything in a day, as long as I accomplish a minuscule thing on a daily basis, my frequency of accomplishment stays roughly the same. Going too long not really getting anything done is when motivating yourself to jump back in the game gets very difficult.