Follow a train of thought to its logical conclusion, and then beyond.
The man who showed me how to photograph work at art school taught me about 'bracketing'. Don't just pick a nice angle and be done with it - you may miss a better one. Move the camera up, until it's too high; then move it down until it's too low. The right angle is in between. Likewise, pan to the left and the right until you've established the outer limits before composing the shot.
One has to go beyond the limit in order to find something interesting. In a world of ideas, stating the obvious has no value. (OK, that's false, but I'm not thinking of polemics, politics, and self-help books here.) To make a contribution, one has to find a new perspective.
(And once found, say it succinctly. The Economist's style guide advises against tired metaphors; "they will tire the reader." Finding new metaphors, just like finding new ideas, is hard work.)