Firstly, you have to find the method that works best for you. I'd suggest that you try a few out and then choose which you find the most helpful, and then use it for your revision and practice questions.
I find a quick spider diagram is the most useful. Firstly I would highlight the key words in a question, e.g.
Describe the conditions which enabled Hitler to consolidate power in 1933.
Describe -means you don't have to give an explanation or a 'why' answer, but instead describe the key events.
Conditions- this is what you are describing, e.g. Treaty of Versailles, Wall street crash etc.
Enabled- this gives your answer direction, you know the conditions must be relevant to Hitler coming to power, and could be considered in some way responsible for his success.
Consolidate power- again this is more about giving your answer direction, this phrase will help you keep your answer focussed and concise.
Of course you dont need to write all of this down in your exam, but highlighting the key words will help keep your answer focussed and make sure you answer the question in front of you. Take the time to read it slowly before you prepare an answer.
Then I would draw a rough spider diagram, choosing three key events that answer the question, this gives you three paragraphs straight away. For each event, then I would write a few words describing it, and more importantly, about why this event was so significant. Lastly it is important to show your own voice in the answer, which can be done by ranking the three events in order of significance.