Like a hungry predator sensing blood, the 'to-list' will always exhaust and out-run you, leaving you defeated and cowering behind a screen of e-mail, dreading another day.
There is another way: work from a 3 by 5 card which highlights your vital few, high-payoff activities. Ignore the trivial many. You can't do it all: the predator is lurking, ready to pounce on the fatal human weakness; trying to do it all and being addicted to the unprotected and swampy by-ways of irrelevant minutiae.