Case studies. They can be the make or break in an exam. Basically, what you'll notice is that most case studies have generic consequences.
And as my teacher always tells me: TAKE IT FURTHER.
For example, if you were doing tourism, and the effects of tourism you could say that it creates jobs. [1 mark?] But then you should go onto say that now people have jobs, they have more disposable income, therefore increasing their standard of living. [2 marks at least at this point]. Then you could say that now that people are getting money from tourism, they pay taxes to the government. The government can then reinvest that money into things such as hospitals and infrastructure, therefore causing the economy to grow. [4-5 marks]. All that stemed from one little point about jobs.
So basically, develop your points. So if you know 2 or 3 points that are specific to a case study (e.g. the one child policy was successful as projections show that without the one child policy, the popluation in China would be at least higher by 230 million poeople) that should be enough. As long as you can develop points.
Good luck with your exams.