I love using the Easy Angle Ruler. Bonnie Hunter from quiltville.com explains how to use it with pictures. I like that you add 1/2" to the desired finished size, cut your strips then place them right sides together. Then cut the triangles with the ruler, flipping it back and forth down your strip. Since they are right sides together they are ready to sew. You can also mix and match the parts. With a corner nubbed off, they show how to line up, and once sewn they come out the correct size with no further trimming. If I see 1/2 square triangles in a project I translate the directions to use this ruler. I used to make them oversized and trim them down but not since I started using this plan. It comes in two sizes which meets all my needs so far.