I prefer to cut 2 squares one inch larger than the finished size I need, mark a diagonal on the back of the lighter fabric and sew a scant 1/4" from the line. Cut, press & trim to size. I do the same for QST's only those squares are cut 1.25" bigger. Even if I have to make more than I need it is still easier & more accurate for me. And Starch, Starch, Starch! That is the best tip for any bias cuts--triangles, diamonds, parallelograms, kites & circles.
Sometimes cutting the points off makes it easier. Another reason I prefer my method. The points (dog ears some people call them) get cut off during trimming.