There's a material we used to use in colorguard that I've used on other occasions and for costumes myself that would be perfect for that. It's called lame'. It's shimmery, light, and transparent enough to let a little light shine through and still not be completely see through where you don't need it to be, as long as you find the one that suits you and the right color of course. They make it in the iridescent colors so they shimmer and such or have a look of multiple shades of the color on one piece. Only big thing is, it's not exactly the greatest feeling thing against your skin, but not the worst either. There's also a different kind that's probably going to feel better to you and get the look you're wanting, but will cost a lot more, called fairy dust organza fabric. Not sure of it's transparency, but it shimmers and glitters and is very pretty. Even the name fits! I'd go to a JoAnns or maybe Hobby Lobby, or a Hancock Fabrics place, and check it out, see which you like better. (take some printable coupons off their websites, and save a bit on the per yard that way too! The specialty fabrics can be kinda high. I always check the sites for sales or coupons and get them in the mail too. Saves your butt when buying $6 a yard fabric sometimes!)
My opinion- to make this, this is how I'd do it (I'm making a Poison Ivy with craft leaves and attempting it in a similar way, and I've made a butterfly costume for a little girl I know using some of this....and it turned out really well.)-
Find a one piece swimsuit that fits you good but just a tad bit tight. I'd get a light color green or white if possible. If it's not a strapless, take off the straps, and trim down the sides and front where you need the body suit/dress to be, and either sew or liquid stitch seams. Then add grommets down the sides at the hips where the lacing is with a couple inches between the lines of grommets, using the smallest silver ones you can find. A green sharpie will color those well to blend them in. Then cut the fabric out between the lines of grommets, and you got your two pieces, front and back now, of the bodysuit. You add your layers of leaves on the body suit, making the dress front and back, etc, and use fray check on all seams everywhere so no unraveling happens. Where the leaf material covers the grommets on the sides where your hips are, let them, so no one sees them, and make sure to turn over a bit of the green leaf to the inside too to hide the bodysuit seams, and then make tiny holes through the layers of fabric through the grommets, and fray check or use super glue gel over the holes on front and back. It seals the hole so it won't spread. When it's all dry, find some shimmery lace ribbon or string to match the leaves, and make it your laces, and lace up the hips (fray check ends of ribbon too! You don't want that coming unlaced at all! And make sure it's strong enough to actually handle being a lacing. If afraid, use some thin white leather lacing like used on sides of leather biker jackets or making bracelets, and cover it by rolling up scraps of the leftover leaf material over it and gluing it on, and make your string that way). Then just make your arm and ankle bands by stitching or gluing on fabric to some thick elastic so it won't slip around, and then all you got to worry about is wings!
(I've made those too, I can help with that if you want. Not going to ramble on and on if not needed.)
