Okay, so you need to measure the place where the valance is going to hang. For example, mine was 145 inches total, going around the corner, etc. I wanted my finished length to be 6 inches. So I cut the green and red strips 2 inches and the apple fabric was cut 6 inches. I used 1/2 inch seam allowances.
For the bottom strip, first sew it like this, with the right side of the strip to the wrong side of the main fabric.
For the top fabric sew them right sides together.
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 hemmed each end of the valance and then on the back side of the top strip, I folded it down and then zig zagged a half strip of the other velcro all along this. You can see I put it just about 1/4 inch below the top of the fabric.
I hope this kind of makes sense. Please ask questions if it is not very clear.