How can I improve my answers for source-based questions?

The key to approaching source-based questions is first to make sure you've noticed all the main aspects, for instance by using the acronym PURER BIN (PUrpose, REliability, Representative, BIas, Neutrality). This would involve looking at who wrote the source, what kind of purpose it would have intended for, how accurate you think the content is etc. Take a few minutes initially to have a think about these before then looking at the questions, and specifically the wording (e.g. how useful, compare and contrast) AND also the total number of marks given. This is a key indicator of how much detail you should give. Then write your answer with the PURER BIN ideas in mind, but geared around the wording - for instance for a 'how useful' question, focus mainly on for what purpose the source was intended and how neutral the content is - which is where you can bring in your own knowledge to gain higher marks.