Thinking that I would be clever, I began this one with a cylinder rather than a sphere. I then used a second, slightly scaled down cylinder, along with a boolean modifier, to cut out the mass where a user of the mask would put their face. This, I believe, led to problems when I cut eye holes through the mesh. Things got a little messy there, and in the end I opted to minimize the damage that I couldn't repair, use a flashy material, and carefully pose the mask to limit the visibility of those problem spots.
Mad Squid Productions™