I too use car window shades, got mine at Big Lots for $1 piece. I went with the silver on one side, white on the other..because I didn't want to feel like I was sleeping INSIDE a baked potato...thinking back, it doesn't make any difference because the curtains cover the shades when in place. I took a hint from the office and bought some Cube Clips. Our cube walls are covered in burlap and NOTHING will stay, unless pinned with a cube clip or long pin.
I'm tracing the window size/shape and extending the pattern by several inches all the way around. The benefit is when the weather is cold, the window frame is also covered and helps to prevent condensation. The clips are nearly invisible when the curtains are in place which is nice, because they're left in the rat fur "permanently."
Here's a pic of the front and back of the cube clip. The pins are 1-1/4 inches long and hold the shades very well.
The kitchen window is the only one without a curtain. I still use the cube clips there, but after I cut the shade to fit, I think I'll cover the white portion with the same curtain material I'm using for the windows, then resew the binding on. May as well have a finished look!
I know others have used velcro successfully, but I think long term this will be a better choice for me. My Scamp
is nearly 20 years old and the rat fur is in perfect shape. Thinking about using velcro reminds me of how a wool sweater looks like after numerous wearings....get out the piller to remove the fuzz balls.