I bought one several years ago and could not get the hang of it, so it collected dust. However, I just recently finished a quilt with lots and lots of curves (Urban Nine Patch) and I sewed all the curves using the same technique, but with my own quarter-inch foot! No pins, no glue, I simply held the top fabric up off the bed of the machine and focused solely on making the edges match as they went under the foot. If I remember the lessons from the inventor of the Curve-Master foot, this is pretty much how she tells you to use it.
You can do a search on YouTube, there are several videos there that show how the CurveMaster works.