there is no guarantee that you wont understeer. its all about learning the timing/aggression. if you are snapping it/entering aggressive, you need faster and earlier countersteer.

if you are entering solid, but not crazy insane, then you'd need earlier countersteer but not a ton of it (turn the wheel slower, but dont wait to do it).

or you got your lazy entries where you are kind of waiting on angle to build. turn little later and slower...

there is no 'THIS IS IT' way to explain it, its all on feeling. its always going to be a guess, but the more seat time, the less it feels like your guessing. there is not a single way to enter. sometimes the turn is slower than the run up, sometimes its same, sometimes its broad, sometimes its tight, sometimes its decreasing or increasing radius. all these things can mean you should enter with more/less aggression and angle. its all learning. this is why it takes years to get decent and then more to be able to figure out a course on your own.