Although I always do my own taxes, and it usually is a fairly smooth process, it is also time-consuming and sometimes stressful.
I’m usually quite meticulous about hanging onto even the smallest receipts until I’ve accounted for the spending. I even record the 50¢ or so I pay for snacks that I bring home from work. Of course, sometimes things slip through, and so every so often I compare the cash I have with what I think I should have, and the difference goes to miscellaneous expense and/or my best guess. Because I am so careful, it really bothers me when I have a bill that I cannot account for, or when a discrepancy shows up in a balance. This doesn’t happen too often, but there’s usually one or two snurks in each year’s tax preparation.