I go to a recycle center where I can get sample books of fabric for a quarter. Depending on the weight of the fabric, the seams are way too thick to lie flat. What I do is use the block joining method in this tutorial
http://www.quiltingboard.com/t-60764-1.htm
Scroll down in the tut until you get to the place where she joins the blocks.
I use a Flat 1" strip on one side and a 1 5/8" folded strrip on the other.
You wind up with a reversible item.