DIY? Tell me more.

what you'd do is spray adhesive the fabric onto regular roller shades. for the valance, measure the drop from the ceiling (or top of window) that you want. add 1/2" for hems to 3 sides, and 1" to the top for hanging.

take a piece of white fabric (bedsheets work well) and cut it the same size as the valance fabric. place the two right sides together and sew a hem 1/2" from the bottom, and up the sides.

turn it and iron it flat. fold over the 1" on the top, and iron the fold in.
either sew on some velcro, or staple up with a piece of lattice to keep the fold sharp.
if stapling, first staple the valance up on it's own, starting from center, then go back and add the lattice piece.

velcro would be easier to remove and wash, but the stapling is generally more secure.

also, if you staple it in, make sure you take the height of the lattice piece into account when you mount the hardware for the roller shade.

and if you don't sew, you can use iron on hem tape or stitch witchery to make the hems. it'll hold just fine for a valance.

Wow. I'm afraid my window coverings would look like I made them. I better stick with a professional.

oh, another thought.
for the rollers themselves, add 1" along the sides and 2" along the bottom, then fold those extras over 1/2", and wrap them around to the back of the shades and glue in place. the 2" on the bottom will cover the weight bar, and the 1/2" on the sides will wrap around and help keep the fabric in place.

it'll also fake a custom made one much better that way.

you can get white or cream shades inexpensively and cut to size @ HD or lowe's, too, so you needn't spend lots of money.

for the height, i'd measure the height of the window and add 6", just so that there's a few rolls of fabric extra, in case they get pulled too far down.

the fabric could be cut up remnant fabric or bedsheets, or curtain panels.
the fabric will make the roller shade a bit thicker when all rolled up though, so mount the hardware a little farther down.

hope that helps!

no worries, it was just a thought. :D

I would love to try it sometime. Thanks for the detailed suggestion.