"You'll see I only wear gray or blue suits. I'm trying to pare down decisions. I don't want to make decisions about what I'm eating or wearing because I have too many other decisions to make." That is former President Barack Obama explaining his style choices and alluding to the concept of decision fatigue. When we are engaged in a long session of decision making, our ability to make good decisions will begin to decline. The brain is like a muscle in that it gets tired and needs time to recover. By removing trivial decisions, Obama is able to dedicate his brain's limited capacity to more crucial decisions.
Even though your decisions may not have serious effects on the economy or international relations, there is a time when you'll have to make hundreds of decisions over the span of several hours. B or C... stick with it or guess and move on... Sound familiar yet? Yup, the day of your SAT or ACT test. Considering the stakes of these tests, it might as well be as stressful as the President's job.
You can use this strategy to ensure that you are starting your test with a clear and refreshed mind. It may sound silly, but you can shift all your tiny decisions on test day to the day before and get them out of the way: what you're going to wear, what you're going to eat for breakfast, what snacks to pack for the break, how many pencils you're going to bring, etc. Why not just have it all planned out beforehand? There is certainly no downside, and the upside is that each frivolous decision you eliminate from your big morning will lead to better decisions on your test. If you find yourself starting practice tests feeling pumped, but by Section 4 you're unmotivated and falling into bad habits, then give this a try.
Fatigue and stress are major detriments to good decision-making. You can control fatigue by making sure you get a good night's rest, limiting unnecessary decisions on test day, and practicing full-length tests to build up mental stamina. You can control stress by going into the test prepared, planning your test-taking schedule so you have time to take a second test if needed, and knowing what to do in common test-taking scenarios (e.g. not knowing a vocabulary word, blanking on how to solve an equation, etc.). Feeling in control is what will give you the confidence you need to make great decisions.