These are more-or-less in order of IMPORTANCE for me to be able to learn and teach art.
#1 ERASER - Staedler-Mars white vinyl. A good eraser is the best psychological defense against the debilitating fear of mistakes. I may be best to teach students to wait until they have found the correct line before erasing. I saw this well illustrated in an early Picasso self-portrait.
#2 PENCIL - 6B - easy to make tone that shows more than 2 feet away.
#3 CLAY
#4 PAPER
#5 SOMETHING FOR COLOR
#6 ADHESIVE AND FASTENERS
#7 WOOD, METAL, PLASTIC AND OTHER MATERIALS