When it comes managing personal tasks and to-do’s the best piece of advice I ever heard came from Jason Fried of 37 Signals in the context of product development.
Instead of keeping an endless log of all the user feedback that came in he would ignore everything until he noticed the same issues being repeated again and again. This signalled importance and so became a task to be noted and addressed.
I have repurposed this behaviour in my own life. Instead making endless lists and notes of things I think need to be addressed, I let everything go and don’t make a note of anything until it keeps coming up repeatedly, which indicates its importance.
Apart from simplifying my life dramatically I also came to discover what was really important and what could simply be ignored, which turned out to be a hell of a lot!