I finally figured it out: how to read out of a textbook without falling asleep. This may not work for everyone, but for me, it really helps to read the text outloud to myself. Reading a textbook isn’t like reading a novel; it can be quite dull or boring, even if the content is somewhat interesting. Try it. Read a textbook chapter for homework and read it outloud to yourself.
It helped me just get through 70 pages of my history book in one sitting. Usually that type of reading would take me at least 7 sittings all interrupted with 10-15 minute breaks. At that rate, it would have taken me HOURS to get through all of it. Instead of taking about 7-8 hours (including all the breaks), it only took about 1.5 hours!
Because of this new reading technique, I have thoroughly increased my efficiency and comprehension. Increasing efficiency AND comprehension greatly decreases the time necessary for review before a test. The more the brain can comprehend with the first read-through, the less that material has to be reviewed.