As a beginning photoshop user, I, personally, would LOVE to get an advanced tutorial about brushes, their settings and kinds, which sets to use for art (for instance, your way of doing skin and hair is just stanning).
Or, for example, an outline tutorial. Today I’ve found out, that versions of photoshop before 2k18 don’t have the ‘smoothing’ option. Idk how important that one is for an outline work, but would love to know, whether I should really care to get a newer program or not.
Generally, coloring gives me lots of trouble, as much as shading >< But that’s for drawing attempts.
As for the beginners, I think, it would be useful to introduce people to some simple features as poses making or backgrounds for splashes and such. Maybe also introduce simple and useful brush pre-sets, (stars, snow, rain, grass and so on), techniques of turning day backgrounds into night ones. It seems pretty popular around here. It seems pretty frequently asked around, but that’s just from my short-term experience 