Hi @sanne, I just saw this post, I´m starting to study facial gesture and came with this ptoblem too, thanks to your tip it kinds of helps to understand the concept, however it gets a little confusing since there are little or none videos doing gesture or sketch drawing doing expressions or face, if you know of any link or could show us a sketch it might help a lot.
This are the steps I do, and I find them not very usefull.
1.-draw the head circle
2.- draw the vertical and horizontal line to see where eyes, nose and moth should be
3.-draw the face outline
by this time the 30 seconds have passed and I couldnt do the expression :/, so this is not helping me at all