Where did I recently read of a Pentagon general describing her approach to getting things done ? Essentially:

1. List everything that you need to do,
2. discard it all except for the 3 key items.

Fairly extreme, and perhaps middle ground is typically more fertile in civilian life, but it could be argued that OF is really best used as a circular file.

Capture everything, and then quietly discard. Those 3 key things you will probably remember anyway, and with some radical pruning you may well see (or find them) them much more clearly. Most of the rest is reverie, or other people hoping to sub-contract some part of their 3 things.