pkatz
This one definitely needs to be taken with a grain of salt, because it is not what would be classified as a behavioral suggestion. I try to limit my intake of stimulants before I take tests. The one time that I was hopped up on caffeine (I mean really jumping) I felt good on the math section, but kept skipping around in the verbal passages. On this one in particular as Akamai would say your mileage may vary. Might have the opposite effect on some people, which is why it's good to know your own response to caffeine intake, nicotine etc. Rarely do such chemicals have no effect.
I also try to delude myself into believing that the material is engrossing by reading the first two sentences of boring passages very actively. The more I comprehend the first paragraph of a passage the more likely I am to enjoy (don't laugh) what I'm reading. If you can make the most boring aspects of the exam interesting it is less likely you will lose focus.
Good advice. I also try to "delude" myself into taking an active part in reading. I don't try so much to force myself to "enjoy" the passage. I thnk much rather I immediately look for the main topic, then read the passage with a critical eye as to whether or not the author is making his point. Taking a active role in reading the passage, especially the first time through perks up the energy level naturally and really helps crystalize what I am reading. Believe it or not, people who read "actively" can often answer every question without going back to the passages (or with minimal rereading).