anyone here using a root touch up kit for grey hair that blends naturally?

this might sound dumb but i feel like every time i try a kit it ends up looking like a mistake after a day or two. i either get that weird dark line or it just cakes up and looks fake. i’ve been managing my greys at home for a while and at this point i’m just tired of the guesswork. what actually works for you guys that doesn’t look like i jumped in a dye bucket and panicked? specifically stuff that stays put through sweat and a light wash.