i think it is definite trial and error
the previouse 3 months it leaked really badly.... NO idea why... put it in the same as before
o bad i bought extra washable STs...
this month it has not leaked at all, as was the case for the 1st 21 months...
i WISH i knew what i did differently, but i dont!...
i think you just get to know whe it is correctly or not.
when mine is in properly i cant feel it at all.
i have no stem at all on mine
also dont do what I did when trying to push it up higher.... i pushed up and managed to turn it inside out inside me
seriously thought id be going to A&E but managed to get it out eventually
(now if it isnt high enough i remove it and start again )