I am most accurate when my stress level is the least. The best time for me to shoot for accuracy is first thing in the morning before I am exposed to the normal stresses of life and when I'm fully rested and recently fed (right after a light breakfast). It's also cooler in the morning and usually less windy. I shoot in the direction with the sun at my back so that it illuminates my target and causes no apparitions in my optics. I make sure that I am completely comfortable and have eliminated all body urges. I do nothing (physical exertion) that would raise my heart rate or my blood pressure; that includes clearing my mind of all but one thing....shooting. When all these conditions are met, I'm at my most accurate.
There's also another time when I'm most accurate, and that is late at night long after the day is past. It's pitch dark. No wind. No noise. I'm the only one in the neighborhood that is awake. And there is a coyote at 80 yards in the crosshairs of my ATN XSight mounted atop my hotrod Condor! Only then is the silence broken, and that with the equivalent sound of a wooden Louisville Slugger smacking the side of a ripe watermelon as another coyote bites the dust. That's when I'm most accurate.
If she thought it would do any good, wifey might say: "Hon, you're gunna drive me to drinkin' if ya don't stop plinkin' that hotrod Condor" (and come to bed at a decent hour).
