Just write out the main points for each paragraph first and as long as you have them learnt off you can go over the rest of the paragraphs you have written out or just make up the rest during the test. That's what I do anyways ..
Try to include housing, food, tools, work, (religion and burial customs) in "diary" accounts. (The ones where you say I am a monk, hunter gather etc.) Learn off 1/2 facts on each and then you can expand these points.