What to be thinking when standing over the golf ball?

im a good golfer, probably around a 3 hdcp, but i stil feel like im not reaching nearly my potential. i read everywhere you're just supposed to chill when your're about to hit a shot, but i cant seem to do it. i've tried visualizing the target, but that doesnt work because then i feel like my swing goes to hell. im just wondering what i should be thinking when im standing over the ball about to hit a shot? or a better question, what are they focusing on? does anyone know what the pros say they think about? thanks, just trying to get better!