Hi,
Here are a few tips i used when modeling these quick 10minute each blendshape poses.
I mostly use mask, move topological/move, smooth, and clay buildup brushes for these. also original model/design.
pose 1:
to get how much to move nose up by, used reference to approximate by one eye
pose 2:
made masking cover more of cheek so could move lip corners wider then resting nostril
here using rotate tool to get rolling of lips
( i found using a time limit actually helped the sculpting process because it forced to look for and create the most important areas of expression. later when these skills are built up i may try increasing the time limit to begin sculpting details of expression on a higher resolution mesh )
Hope this is helpful,
cheers,
Nate
Inspired by
Philippe Faraut's Anatomy and expressions in clay (philippefaraut dot com)