Further below is a menu of lessons I used to teach my students at PSU. Here's me teaching in '13. I started '94 and retired in '15. What have I learned? . . .
Focus — convey something in an artwork. Could be simple like an object, to complicated like a feeling.
Purpose — only use elements like media, hue, value, composition, etc., which further my focus.
Unity — combine elements so my focus will be a viewer's first impression.
Pencil — Two Blackwing pencils. One Blackwing with a a sharp point and a second one with a blunt point. Other pencil brands are good as long as they are 4B, the only grade I use. Pencil extenders. Canson pure-white drawing paper, a white eraser, a kneaded eraser, small tortillion for eyes, and drawing boards (different sizes) onto which I tape my paper and reference photo.
Watercolor — I use transparent watercolors by Schmincke and Daler-Rowney (pans not tubes), round sable brushes size #3 to #12, Arches 140 lb cold-press paper, masking tape (to tape down the paper on all sides since I don't pre-stretch the paper), small oil-paint brush for removing paint, latex masking fluid (I apply masking with a child's nylon watercolor brush), various plastic pallettes, an old t-shirt rag, and painting boards (different sizes) onto which I tape my paper and reference photo.