Hi,
Well, we all have our individual technique.
Follow the destructions in the box.
Or, I place mine inside the arm, not afraid to use a razor on stray hairs? (Though the inside arm is smooth.)
Normally I do a change after a shower exfoliate the area the sensor is to be sited, dry. Then clean with the alcohol wipe.
Dry again with a hairdryer. Especially in winter warming the adhesion area up.
Prep the sensor then bang. Making sure the edges are firmly stuck down.
I've never personally lost a sensor prematurely to date. & tested the adhesion on on for 17 days till I got bored with a 3 day dead disk.
The above may sound like a bit of a faff. But most of the prep is done whilst bathing anyway.
I also don't use deodorant till the sensor is in place.
Hope this gives an insight.