Kaffe Fassett has a really beautiful design using 60 degree diamonds called Rosita. There's a great video tutorial on creativebug.com that she could check out (free 14 day trial). It's really quite simple. All she does is line up the one side of the triangle ruler with the corner of the diagonal cut & cuts. It somehow manages to form a 60 degree diamond. So cool!
He & his partner Liza Lucy use the Clearview Triangle Tool Super 60.
http://www.ctpub.com/clearview-trian...acrylic-ruler/