My school had it as an elective that I didn't have room to take, but there was a senior I vaguely knew who got a 36 (and really good on the PSAT, he was a National Merit Finalist), so I did tutoring from him.
Uh fun fact, I took the ACT 3 times (once each in 10th, 11th, and 12th grades) and got lower scores the latter two times (Tho the first time was with tutoring)
On the reading section, always read the questions first, so you know what to look for when you go through the reading. And underline as you go
Math just the basic stuff of don't spend a long time on the ones you're unsure on, do the ones you're confident on first.
Science is basically just reading 2, so just figure out which random stuff you can ignore, and just focus on the info that is useful for the problems
The main thing is to just take a bunch of practice tests too, so you're used to the kinds of problems there are. Ultimately there's only a few different types of questions on some different parts, tho I don't remember them all xD