Science backs up the idea that vacations give us a fresh perspective on things. The main takeaway is that your mental efforts are most valuable after a vacation, so you should make use of this period for decisions requiring this state of mind: you will have better potential for insights and creative solutions to problems that you were previously stuck on. Perform routine tasks for when your mind is not fresh, and no deep insight or new perspective is needed.
More generally, just recognize that you find yourself shifting among various states, and then use your peak mental states to address your most significant decisions. At the same time be aware of when your mind is weak, saving yourself from the consequences of decisions made in that state.