If you do any type of Blender sculpting, you should know about Mask Tools. The Blender Add-on lets you create masks from a geometry selection. This is a much better way to derive a mask, than painting one. Painting masks for Blender sculpting can leave you frustrated, especially if you are trying to mask out some tight spots that have a lot of details.
Being topology-based, Mask tools lets you simply select the parts of the geometry that you want to mask out, and then converts that selection to the mask.
How does it work? Check out Caetano Veyssières‘ video that shows how Mask Tools can really be a great tool for Blender sculpting.
Mask Tools is free to download, courtesy of BlenderArtist’s Yiit post.