(1) Unlearn the "large team workflow mindset" and embrace the "single developer mindset" again. You don't need a plan, a Kanban board or a bug database, just an idea in your head. Get rid of "big languages" which are good for team work, but just a hinderance when working alone. In my case this meant: dropping C++ and embracing C (today that would be: Zig). Focus on getting shit done like when you started out with programming instead of agonising over design decisions. It's better to throw away something that doesn't work than wasting too much time upfront with planning (and then it still won't work). At least you still learned something valuable. Try to do the 'planning' part passively in the back of your head out in nature while taking a walk or some other outdoor activity.
(2) Pick a challenging problem where you have no idea yet how it works, but which you would like to know. In my case this was "home computer emulators".
...well 3 steps, step 3 would be: don't set yourself any deadlines for this sort of "fun stuff".