Any advice on how to improve ACT score?

Answered

Many students study for the ACT/SAT the wrong way—lots of practice tests are not the answer. First, within each section, questions are divided into content type. In the Reading section, you might get questions about Author's Intent or Making Inferences in the same way you might get Pre-Algebra or Triangle Geometry in Math. To get a higher score, you need to understand which of these content types you are commonly missing and intensely study those. You can expect a certain number of each question type on the test. It's not as effective to study the material you're nailing every test.

Second, you need to finish each section (if you aren't already). To get a 35 or a 36, this means you're missing 1-2 questions (with some variability by section, dependent on each test's curve). If you're guessing at the end (never leave a bubble blank), you're obviously more likely to get those wrong. That margin of error is the difference between getting a high score and a lower one. If you are finishing, every second you have left over should be for review. You should be certain that the questions you answered are correct.

Part of getting faster is practicing sections under timed conditions and part is knowing the structure and pattern of the test well. For example, the Math section gets progressively harder, so you should be spending less time on those early questions (and always getting them right—all questions are created equal, points wise).

Finally, some colleges will superscore the ACT, taking your best sections from each test date. It's worth seeing if the schools on your list will do so before taking your next test. Then you can narrow your study even further, to a section or two.