Practice! There's no workaround or fast track. I had clb10 on first attempt without preparing (im not a native speaker) while others had to retake it 3 times. It depends on your level. Even native speakers who speak well might not do well on reading level. Remember there are 4 sections, you have to score well on ALL 4 to get CLB9. Do sample tests and evaluare your level. Read, listen, talk etc... there ielts prep classes you can take as well
google is your best friend here. Look up IELTS practice tests, sample exams, etc.... their site has resources, after you enroll for tests they'll give you training resources as well, there are IELTS prep courses... you have to look it up to estimate your level and see how hard you need to prepare