Hello, so i wanted to get into mewing and maintain a proper tongue posture but there are a few things that i dont really understand and id like to get some help from you all if possible

-To get into the proper posture i put the tip of my tongue in between my front teeth towards the top where it meets the gum, from here i try to push my tongue back up towards the roof of my mouth, here i have 2 questions: 

Does my tongue need to be inbetween my molars, as in do i have to have it fully inbetween in a bent shape? because when i try to do this i feel like i clench my molars a bit too much and it doesn't feel right.

When i try to mew saliva builds up between my cheeks and teeth , how am i supposed to deal with this ?

Mostly these two things are what i  have trouble with... Any tips on what a beginner should do would be very helpful aswell! I can further detail if there is anything specific that i would need to say. 

Sorry for the general question but i wanna know as much as i can since im new.