My style is pretty simple and I prefer using texture and contrast over lots of color or pattern. I decided to go with a super inexpensive creamy cotton twill for window panels in the dining room and a roman shade in the adjacent sitting room/office.
Wide greek key trim in black & khaki - also inexpensive, from Hobby Lobby!-finishes them perfectly and is classic enough that even I won't grow sick of it.
Note- This room really needs a chandelier but cannot make a decision on which one to buy.
I used a single width of the fabric to make the panels. With three windows in the room, I didn't feel they needed to be any fuller. They are lined with regular lining. I debated either using a heavy napped lining to make them really luxe, or no lining at all to make them more casual, but in the end decided to go with a standard inexpensive lining fabric (which still was as much as the twill!). I went with double euro pleats because they are my favorite.
With a 40% off coupon, the trim for 6 panels and the shade from Hobby Lobby was a little over $100. You could easily spend A LOT more on trim and I love the way it looks.