Some people only read 3 of the 4 passages on the reading section of the ACT(which is a huge time crunch), and focus on those 3 sections. This strategy isn't all that great if your goal is a 36, but if your goal is a 25 it can be helpful. Based on what your goal is, there are different strategies you can use to achieve your goal.I am not sure how having a 'goal' in mind before taking these tests makes any difference.
No one should ever take a standardized test with the idea is it OK to miss a few questions .
You should strive to get the best possible score.