A lot of well known patchwork blocks patterns consist of squares and triangles (half square and quarter square. The template sets A and B by Marti Michell are based on this: they contain squares and triangles, with which you can made a enormous array of blocks. The templates are made of the same acrylic material as quilt rulers, so they can be used with a rotary cutter. First, strips are cut of the right width, and then the templates are positioned on the strips, to make the second cut. Each template has double blunt corners for perfect alignment. The blocks go together past, easy and perfect!
The first template set, A, has 7 parts (3 squares and 4 triangles). The largest square is 3 inch.
The book Encyclopedia of Patchwork Blocks part 1 contains a lot of blocks you can make with this set.