Easy abstract painting that anyone can do! Just blob the paint on the canvas in random spots and blend! (would be interesting how students could make different pictures w/ the same colors and same blob positions)
DIY: Reupholstering & Tufting A Chair - this is an excellent tutorial on how to give an old, dated chair a new look. A new look for a $12. thrift store chair! If I can do this, that'd make my life 100x better.