Immerse yourself in the language for sure. Doing well on the Paper 2 especially requires good knowledge of vocab and listening skills, so the more Spanish media you read and watch the better off you are. For the speaking assessment and Paper 1 just practice and make sure you know the rubrics really well. Write passages in Spanish and run them through a grammar checker to check for any mistakes you make and look at past papers to get the formatting down. Spanish to english, translate back to spanish, compare with original = gaps.
