How to increase my ACT score?

I got my ACT scores back today and I got a 28 composite total. How can I increase this score to at least a 32? I did not study at all going into this, as this was more of a test run to get a feel for the test. Should I pick up a red book and just use that book completely? My individual scores are:
English: 25
Math: 31
Reading:30
Science: 25
Essay: 8/12 (24)

I know Math and Reading are obviously my strong points, so what would be the best way to increase the other ones? Thanks!

Buy the practice books and get cracking. D practiced 3 or 4 hours every Sunday for about 3 months. You can do that if you are a junior. She improved about 4 points from 32 practice to 36 actual

@‌shak567

The best way to study for the ACT is to practice with REAL ACT tests. There are 5 tests in the Red ACT Book, 3rd Edition. ACT released several tests in booklet form.

Time each practice session to simulate the real test.

English 75 questions in 45 min.
Math 60 questions in 60 min.
Reading 40 questions in 35 min.
Science 40 questions in 35 min

Score your test and Review only what you got wrong after each practice session.

I suggest the following schedule:

Take 1 section each school night/with review for 4 nights/week.
Twice per month on a Saturday or Sunday take a full ACT test/with review.