Extra Credits is a great channel for getting ideas about ‘game design’. Not from a technical perspective, but from a design perspective. They ask questions about why games make the choices they do, and talk about the ramifications of those choices. A lot of this applies to things beyond games.
They also do Extra Credits History which is interesting as well.
Diegetic UI - Realistic, or Distracting? - Extra Credits
Dude worked for blizzard for a while. Great artist, has a series for teaching drawing. If you want to learn how to draw using photoshop and a drawing tablet, this is probably the guy you want to follow. Though I would say you don’t want his videos, you want his classes on gumroad.