Start with a diagnostic mock test to understand where you stand, then take full timed mocks regularly using official materials like the practice sets. Read every day (newspapers, editorials, academic articles), and listen actively through podcasts or TED Talks, summarising what you heard in a few sentences. Write something daily, even 150-200 words, focusing on clear structure, and speak out loud by recording yourself on opinion questions and playing it back to catch hesitations and grammar slips.