Private tutor is the best if you can afford them. Live online tutor generally cater to big audience so the pace could be too slow or too fast for you. They could also highlight areas that u are already good at and omit areas that u will will require more attention too.
Look for reputable tutor online or ask around for reference in your local area.
This is what I did--bought a prep book, planned out a schedule for study/review of the entire thing and I scored much higher than I expected to. In addition to the subject reviews, the tips about how to succeed on standardized tests were invaluable (when you should guess if you don't know, when you should skip a question and move on quickly, etc.). It helped me feel calm going into the exam.