GCSE history essays follow a general fromula so once you get the hand of it you should be able to write any essay.
A short and precise introduction is necessary, the introduction should include both sides of the arguement and then your judgement (basically which side you are going to argue for).
Next you have the main body of your essay, there is no correct amount of paragraphs you should write, as it will depend on how it many it takes to get your argument across (or how quick you can write). However, for a GCSE essay I would suggest doing 6 paragraphs 3 for the argument and 3 against the argument.
When structuring a paragraph I would use PEAL, this stands for: point; explain; analyse and then link to question. This means that you should hit the marking criteria. The last one 'link' is very important and is often forgotten. It is particualrly important as it means you are still thinking and focusing on the question and not going off topic - this also shows a good structure if you are reiterating why that particular point is important at the end of the paragraph (examiners love it!).
You should be careful not to tell the story, but instead to analyse the events, as this will get you the higher ,marks, as it shows the examiner that you understand the content and have your own judgement of it.
Once you have weighed up the argument, you need a precise conclusion to end the essay. It is important that this should not just be a repetition of what you have written in the body of the essay. Instead it should be clear which side of the argument you believe is better and why the evidence shows this. Furthermore, no new evidence or points should be brought in.
Clearly, everyone's style of essay writing will be different, but sometimes sticking to a formula is easier until you have figured out the way you like to write an essay.