For the bottom strip, first sew it like this, with the right side of the strip to the wrong side of the main fabric.
Then press all the seams open. With the bottom strip, press a 1/2 inch over like it is here to the right.
Then fold the bottom strip up and top stitch it.
Above my window, I have this little shelf type thing and I nailed a half strip of velcro along the whole little shelf.
I hope this kind of makes sense. Please ask questions if it is not very clear.