virtualbernie

You might be interested in the "Add Enough" ruler. http://www.addaquarter.com/products.php I bought one because the concept sounded good but I haven't used it yet...

hopetoquilt

I have the add a quarter ruler and use it constantly when paper piecing. Carol doak explains how to tape a postcard on tp flip down and fold the paper. I use this method but could not explain it if i tried. It works fast and easily. I recommend getting a 12 in or so sized add a quarter ruler ( not the smaller one that is sold)

virtualbernie

The ruler I'm talking about is the Add ENOUGH ruler. It let's you measure how large of a piece of fabric to cut to cover the space you need. I also have the add a quarter ruler and also use it all the time!