Here I basically sculpt an upper lip kindof roll shape using clusters. There are probably lots of better ways to do this (maybe soft mods, lattices …) Here I try using clusters. This is not an advanced face rig the topology for the lips is still quite off. Hope this is helpful.
Basically I try to figure out roughly what the lip vertices are and make a cluster for it.
Here are some pictures
---paint set membership tool
This let me add or remove lip vertices for the roll.
Using a solid brush this helped me to get a little bit of smooth fallouff.
--MEL for selecting lip vertices
A helpful tip for selecting lip vertices. Suppose we've got a cluster on some of the top lip vertices and we want to now figure some low lip vertices. We can open the mouth with the cluster, select the lower lip vertices, use MEL to save selection. Close mouth. Then reselect low lip vertices and make a cluster. This way we dont have to start from scratch trying to figure out lip vertices from a closed mouth default.
---mirror side so less work