It helps to have a back-light. You hold the fabric up in front of it to make sure you are covering the seams with your new piece of material. I made a paper-pieced quilt the first time at a Mariner's Compass class, it is my avatar. I also made a double sized quilt with a lot of pieced birds and flowers.
The main thing I have found is to not try to skrimp too much on the fabric. Fold it in the direction you are going with it to make sure you have enough fabric to cover the area -- plus seam allowance. In other words, leave enough fabric to overlap the next line and trim after the next piece.
When I started, I made the mistake of trimming the fabric before I turned it down where it belongs. OOPS! Make sure to fold it down, press, then trim.
Reading Carol's blog site I saw a great tip about using a tracing wheel to run along the solid line, where you are going to fold to trim, it makes it easier to fold the paper precisely.