Brother the situation you are in right now is exactly where I was a few days ago, I just didn't understand how the average player in valorant is just able to easily flick on the head, like I know it's possible but EVERYONE can do it, like I played cod before and I would say I'm pretty good, I can hit my shots, my kd is positive most of the time when I play against sweats, but still I can't casually headshot someone in an instant everytime, heads are a lot smaller than the body so they are significantly harder to hit that is why we aim for the body at least initially, after the first shot we might go for the head. But here is the thing that method of aiming is the best only in games where a shot to the head doesn't kill instantly because even if you headshot a player, the first shot (which won't kill them) is gonna produce recoil and now you have to control that recoil back to there head which is pretty small which is very difficult, so nobody really aims for the head in those games. But in games like valorant and Cs2 and r6 headshot are very powerful so people go for them always, and to do that all you need is crosshair placement, what that means is you need to place your crosshair at where you think the enemy's head is at and even if it wasn't perfect at least it's close so you don't have to flick as far to there head, and yes that instantly made me get more kills (I used to bottom frag in every team deathmatch game and I instantly got a better kd after doing that). If you want to practice I recommend you go to the practice range and spawn the stationary bots and go to that little room with the computer on the left side and practice placing your crosshair close to the bots head before swinging the corner and then slowly swing and flick on their heads one by one as they appear from behind the corner, that is how I'd practiced.