DIY cushions for patio furniture. Super easy. I didn't have old cushions to cover so I used layers of cheap bed padding foam wrapped in batting. Look here for how to do boxed corners that are not covered well http://craftapple.wordpress.com/2007/09/01/sewing-tip-squarely-boxing-those-corners/
How to spray gel stain or regular stain. It's quick, easy, and looks professional. Especially useful when updating wicker furniture. Also how to change cushions for $10 without sewing! A no-sew solution for upholstery redos. Entire transformation of two chairs takes about an hour!