1. Review ACT skills. Nationally recognized review books can either be purchased online or at any major book store. ACT, Inc. publishes The Real ACT Prep Guide, which provides you with 3 retired ACT exams for you to study.
2. I can't stress this enough, read, read, read. The more you read, the better your vocabulary and grammar will become. This will help in both the Reading and English sections.
3. Find a specialized tutor, class or online program to help you learn the best strategies to be successful on the ACT.
4. In math, you need to identify what you need focus on and find specific information to bridge any gaps in your mathematical knowledge. Memorize those formulas!
5. The Math section becomes more difficult as you progress through it. Break up this section into thirds: Easy (#1-20), Medium (#21-40) and Difficult (#41-60). Make sure you can pass the section you are working on with flying colors before moving to the next.
6. The Science Reasoning section has much less to do with science and more to do with reasoning. It is all about applying the concepts. Practice reading graphs and tables rather than studying science. All of the science required is provided in each passage. Most passages refer to difficult areas of science with little expectation that a student would have studied the material in school.
7. Keep track of time! During practice, time yourself without stopping, just to get a feel of how long the sections will take to complete. Later begin limiting yourself to the allotted duration for each section. Know how long each passage should take and remain disciplined.
8. Develop a customized strategy for each section. Practice that strategy constantly until it becomes second nature.
9. There may be test prep organizations in your area that provide practice tests with diagnostic analysis. A lot of the time, these services are provided for free.
10. Practice. Practice. Practice. Take a full practice exam several times before sitting for the actual exam. Training your body and your mind for the 3-5 hour ordeal of taking this test will help condition you for the the real exam.