Getting a band score of 8 in the IELTS writing test is challenging, but it is definitely achievable with the right preparation and practice. Here are some tips to help you reach that score:

1. Understand the Scoring Criteria: Familiarize yourself with the IELTS writing band descriptors for a band score of 8. This will help you understand what the examiners are looking for in your writing.
2. Practice Writing Regularly: The more you write, the better you'll become. Practice writing essays, reports, and letters on various topics to improve your writing skills.
3. Grammar and Vocabulary: Ensure your grammar and vocabulary are strong. Use a variety of sentence structures and avoid common grammatical errors. Incorporate advanced vocabulary appropriately.
4. Coherence and Cohesion: Your writing should be well-organized with clear paragraphs and a logical flow of ideas. Use linking words and phrases to connect your ideas and create cohesion.
5. Task Response: Understand the specific requirements of each writing task (Task 1 and Task 2) and address them appropriately. Stick to the topic and provide a clear response.
6. Word Count: Stay within the prescribed word count. Going significantly over or under the word limit can negatively affect your score.
7. Time Management: Manage your time effectively during the exam. Allocate enough time to plan, write, and review your essays.
8. Practice Under Exam Conditions: Simulate exam conditions while practicing. Write essays within the allotted time to get a feel for the actual test.
9. Seek Feedback: Have your writing reviewed by a teacher or tutor who can provide feedback and suggestions for improvement.
10. Read Model Essays: Study model essays that scored band 8 or higher to understand what makes them successful.
11. Avoid Plagiarism: Never copy content from sample essays or any other source. Examiners are looking for original work.
12. Proofread: Carefully proofread your writing for errors in grammar, punctuation, and spelling. Even small mistakes can lower your score.
13. Task 2: Develop Ideas Fully: In Task 2, make sure you fully develop your ideas with clear examples and explanations. Support your arguments effectively.
14. Task 1: Be Precise: In Task 1 (for the Academic test), be precise in describing the data, trends, and comparisons. Use appropriate vocabulary for this task.
15. Stay Calm: During the actual test, stay calm and focused. Manage your time well and don't panic if you encounter a challenging topic.

Remember that achieving a band score of 8 in IELTS writing takes time and consistent effort. It's important to practice and receive feedback to identify and address your weaknesses. Good luck with your IELTS preparation!