Based on your range it seems that you know how to do well. If you've scored 12's I wouldn't worry about your strategy, unless those 12's were when you guessed 10 questions and got lucky!
What really helped me was using the 10min break to read. I don't mean read your favorite magazine or novel. Grab a New Yorker or London Review of Books. Find the worst, boring article and during the break take a few minutes (1-3, no more) to scan some paragraphs. Helps me switch from PS to VR.
Also, check your scores on practice tests. I always felt rushed but found I scored much better taking my time and guessing a couple than rushing and finishing early.