Answers:
It all depends on how much time you have.
The most important thing is to become familiar with the types of questions you will be asked. When you know what kind of questions they will ask you, you can answer them right away without thinking about how to do it. It becomes automatic.
If you have over a month, it is best to take the practice test and figure out which sections you are the strongest and weakest in. Once you figure out what you are good at, set that aside and focus on practicing the problems you are not strong at. You can do this on your own, or you can take a class, or you can ask teachers for help. After practicing for a week, you can take another practice test and assess your improvement. If you improved, great! if not, then you will need to keep working on those areas. If you are still strong on the same strong areas from the first time you took the practice test, you can continue to focus on your weak areas. Over time, you will get better when you become more familiar with the questions.
If you have very little time (like a week), I would suggest that you take the practice test, and then focus on your strongest subjects. Make sure you know them well and understand how to do those questions. For the other ones, just look at what they are asking and learn to eliminate answers that you know are not correct. if you can narrow down your choices and make a good guess, you will be in better shape than if you left them blank. You get more points if you guess a question right than if you guess it wrong.
Like I said, the most important thing is to become familiar with the questions and to know how the test works. Once you know that, you can work on learning tricks to answering the questions faster. The more questions you can answer, the better off you will be.