To add on top of what has been said, the best is to practice, practice, practice!
In concrete, with tests, so you can also time yourself, get used to the format, etc.
There are free exams in the internet that you can use for practice (the one of LBS MBA page, Verits prep, as well as some free trials for courses such as the one of The Economist (https://gmat.economist.com/)
The key to success here is not only get practice, but learn techniques.
Hope it helps!