can't manage to create lips on my model

Hi,

EDIT: ok I finally found a way, going slower step by step

previous message

after a few hours of redoing, I would like to ask if you have some tips to make the lips, I cannot create a good shape with Crease / Inflate / Pinch. I tried first with Crease, with multi-res at 3, and trying little by little to create the shape of the lips, then change the multi-res to 4, but the vertices seem to overlap, or the inflate does not help a lot.

Would you have some tips with my blend file?

the image :


Thanks