Standardized tests are hard enough to study for. Do you really need to take the optional essay portion, too? Unfortunately, if you’re taking the ACT, the answer 99% of the time is “yes.” Some colleges don’t require you to take the essay, but many do. If you are 100% certain that the schools you are applying to do not require or recommend the essay—which you can find out by checking the website or emailing an admissions officer—and that there are no scholarships you might be eligible for that require it, then by all means, skip the optional essay.
However, if there is even a 1% chance that you might change your mind, I would strongly recommend doing the essay. During your junior year, you will most likely be inundated with mail from colleges all over the country, some of which may offer you significant scholarships and even full rides. Imagine getting a letter from a college offering you a chance at a full scholarship, but you were ineligible to apply because you didn’t do the essay! (Now, in this hypothetical case, I wouldn’t give up without calling the admissions office and explaining your situation. Still, why take the risk?)
Or perhaps you take a fascinating course during your senior year, and it inspires you to study an obscure field, such as ancient Egyptian hieroglyphs or boatmaking. You had never before realized the beauty of boats, and you want to explore it at an advanced level—maybe even major in it! None of the schools you had planned to apply to offer that major, so you make the last-minute decision to add the few boatmaking schools to your list. You don’t want to find out that those last-minute additions require the ACT Essay test, and that you missed the last test date. Your dreams of becoming a boatmaker have capsized. Are those tears or seawater droplets in your eyes? This watery fate could have been avoided had you taken the “optional” Essay test from the beginning!
To sum up and be serious for a moment, I strongly recommend taking the Essay test even if you don’t think you will need it. Plans change. People change. Make sure you’re prepared.