DIY Circle Vest Tutorial and Pattern from Threads Magazine. This is made from a circle with slits cut or the armholes based on 2 measurements: back width and armhole depth. If you plan on making this please read the comments or make a cheap muslin pattern first.
DIY Easy Shawl Vest Tutorial from Jess Amity. Really easy if you have the right shawl - 2 holes and minimal hand sewing the raw edges. See my archives for lots of DIY scarf ideas from knitting, styling to restyling: truebluemeandyou.tumblr.com/tagged/scarf
DIY Sharpie Lace Vest Tutorial from Alisa Burke. Alisa Burke has a short video (just over 2 minutes) on how she created this lace and (p)leather vest using an oil based sharpie. Of course Alisa Burke is so talented and can make anything look good, but I like this idea.