Hi, I'm working at a grade 9 in French and here are my main tips:
- listen to podcasts (my favourite is Coffee Break French)! In my opinion, they're the best way to practice listening since it gets you listening to the language but unlike music/TV shows, the vocab used will be more relevant as they are geared to language learners and you're forced to try and understand what they're saying (as opposed to just putting subtitles on or blocking the music out)
- if you do Edexcel and have access to kerboodle, there are a bunch of listening practice tests on there, and it's helpful since that's the one skill that you can't really practice at home as easily
- make/find Quizlet sets with all the vocab on the specification (I'm in the process of making them for Edexcel so let me know if your school does Edexcel and I can send them your way!)
- learn some good phrases: idioms, subjunctive, good conjunctions (eg neanmoins, pourtant and ainsi que) - you don't even have to understand them grammatically as long as you know how to use them
- practice little and often
- get to grips with grammar! Make sure you have a solid understanding of the main tenses (near future, perfect, imperfect and present are the most important, but for those higher grades, conditional, pluperfect and simple future are good to know. Subjunctive - not technically a tense but that gets complicated! - can be helpful but you're better just to learn some set phrases than worrying about how to form it, especially since it's difficult to know when it should be used)
hope this helps!