Do all the pressing and sewing at once to save time. Remember that both the hem and the header need pressing. Instead of using rings on the rod, just use the rod. Use two panels instead of one, as this allows the curtain to open up in the middle.
Ensure the curtain does not become stiff and pouf out by spreading the header. Create a more relaxed look by using fewer rings, if you have to use rings, spaced further apart. Hang the curtain 1/2 inch above the sill. Make sure the curtains have a nice body and weight by doubling the hem across the bottom. After washing the fabric, run an iron over it to eliminate wrinkles and provide an accurate cut.