If you are looking for cool tools and hacks to streamline and diversify your workflow in Blender, check out SMIRK, a Geometry Nodes tool created by 3D Artist Krysidian that allows you to craft facial features independent of the head, draw and animate them with Grease Pencil.
The solution is a collection of nodes, mainly the Transparency Boolean, which lets you create "detached" facial features similar to how faces were crafted in Pixar's recently released TV show, Win or Lose.
SMIRK separates the mesh of the head from the mouth, which ensures a free movement, independent of topology. Such a technique is perfect for visualizing expressive emotions, which you can use in animating cartoon-style characters. Krysidian explained the principle of the approach in a video:
