I watched a few tutorials and my lazier side won out when I saw that some just tacked the fabric together to give it the look of a Roman shade. If you don't need it to function...keep watching!
Fold the fabric over and press with a hot iron to get your crease. Slip the hem tape into the crease and press again. The strip melts the two sides together and BOOM! You've got a clean edge.
Wrap the top around a 1X2 furring strip and mount inside the window frame. Pre drill the furring strip to avoid splitting. Attach it directly to the window frame.