This is just a n=1 "study" that I've used on myself. Your mileage may vary.
Invest your time into anything project related. It doesn't matter what you are doing, as long as your doing something.
I know this may sound like a counterproductive strategy, but hear me out.
As is widely covered in the field of cognitive biases, we humans are anything but rational. In fact, we tend to let our emotions guide us to – sometimes – make the wrong decisions when pressured to decide.
The same goes for the sunk cost effect. We tend to continue a behaviour as a result of previously invested resources (time, money or effort) (Arkes & Blumer, 1985).
I.e. the more time, money or effort you invest into something, the more likely you are going to keep doing it. This can have positive or negative effects depending on your situation:
a.k.a. knowing when to quit
On the bad side, this can result in a waste of resources when you rationally know that you should probably quit a project. But you already put in so much time and money, so you continue doing it. Even if the demand is not met, even if the validation fails, and so on.
Please be rational in this case and don't use the following strategy.
And read The Dip by Seth Godin...
On the good side, you can use this to beat procrastination. In my case, I didn't really know what the next step was, because the project ahead was too big and too undone.
Which lead to procrastination.
Basically, I didn't know where to start. It's like climbing Mount Everest and standing at the foot of the mountain.
Now, I knew I had to set up the website, marketing, emails, graphics and all that stuff anyway. So whenever I did not know what to do next, I just did any of those things instead: build a landing page, write email sequences etc.
I collected everything that I had done for the project in a Notion page and made myself a sort of progress meter (just an approximate of course).
Interestingly enough, that is what kept me motivated to finish the project. Seeing that I had already done something had triggered the sunk cost effect in my mind so strongly, that it almost made me anxious not to keep working on the project.
Give it a try, tell me what you think.
Also if you like hacks like this one for productivity, self management and -growth, maybe follow me on Twitter ;-)