I'm starting History Extension in two weeks after dropping English Extension like a hot potato and I'll be frank - I'm in a mix of anticipatory and anxious moods. I think I'll be a-okay with the whole "What is History?" thing... I get abstract topics 
My question is: can someone offer some advice and tips and tricks for History Extension? I can't find any notes or anything on it :/
Hello hello!
Here are my tips for history extension.
1. Consistently work on your major work - DON'T HOLD IT OFF because its a lot bigger than you expect. The major work is a blessing and a curse, because if you are willing to put in the hard effort to do well, you can pretty much guarantee a good internal mark based just on that because its worth 80% of your internal, but if you slack off in that area you're not gonna be in for a fun time,
2. Think about your major work topic early, and aim to solidify it early. I can almost guarantee that you will change your topic multiple times. Everyone I know did. But try and have a good idea of what you want to do as early on as possible, so that these changes don't come to late.
3. READ! A lot of people don't realise how important this is in extension, but if you don't know the main arguments and points of i'd say AT LEAST four historians for both part a and b, then you're running a bit of a risk in the exam when you are gonna be asked to reference two other relevant sources! If you look on BOSTES i think there is a reading booklet or something that is really good. It's over 100 pages with extracts from a bunch of different historians all from different background. Also, if you want a quick - but so worth it in regards to this subject - read, have a look at 'What is History' by E.H. Carr. Most markers swear by it.
4. Practice papers! Really one of the only ways to study, however don't even attempt to memorise extension essays. The question is always going to be different, and even if its not if you are not consistently referencing the source given then the markers are gonna get pissy.
Congratulations for starting history extension! I'm sure you're going to love it because it is a fantastic course

Good luck! If you have any more questions ask away!!