Hi, Emilio!
Thanks for reading and commenting.
That question is the golden one, and it will never have a one-and-only answer because it depends a lot on what you're looking for, your current situation, how your brain works, and what background you have.
For me, the crucial concept is differentiating between deep thinking and shallow thinking.
In my case, I use a different tool for each process/system: Heptabase and Tana.
It works pretty well for me, and they're solid tools with a team we can trust behind them.
Yet, the crucial point is feeling that you have no friction when dealing with information and its processes: capturing, retrieving, linking, and, above all, moving your information into action.
Hope this helps!
Cheers!