The reading sections are fairly easy and the best way to do good on those, is to read the questions first, and then read the section. On the writing portion, take your time. You are given a few hours to do this test for a reason, don't waste any of that time by "finishing early".
I got a 31 on the ACT and a 2100 on the SAT, which are both extremely above average.
honestly, this is the best advice. read the questions over ahead of time, maybe note key words in certain questions and circle lines they refer directly to in certain questions (
"in line 31, the word "stuff" most nearly means..."). i didn't take the SAT because i did poorly on a diagnostic test and did really well on the ACT diagnostic, so I just skipped taking the SAT and got a 34 on the ACT & waiting for my second test date's score to come back (should be any day now). honestly, yes they're changing the SAT soon but it's all a matter of personal preference.
and math on the ACT is certainly harder, i found math on the SAT to be the more common sense one whereas ACT actually has some questions that require you to do math
oh and if you can swing by a bookstore and pick up an SAT reading section practice book if you're that worried about it, it'll have a lot of sample questions for you to practice off of
ACT has math, reading, english, and science iirc. There is an optional reading additive which I'm going to do. I hate the reading comprehension the most.
the optional part is Writing, which shouldn't be optional because if you want to apply to an above-average college you'll most likely be required to take the writing part. the required sections are English, Math, Reading and Science (in that order).