How Do You Improve Aim Without Relying on an Aimbot?

I have days where my first bullet is a headshot and days where I'm apparently trying to negotiate with the wall behind the enemy. I get why aim-assist tools look tempting when your mechanics feel random, but I'd rather fix the basics first.

What's a realistic warmup that doesn't turn into a 45-minute ritual before every game? I'm thinking a little range work, a deathmatch, then focus on crosshair placement in actual rounds. Too basic or about right? For contrast, aimbot settings in our guide describe what automated aim claims, which is not the same as practice.