Whether you collected them as a kid, or want to make fun of the modern-day troll found in comment threads, this costume is quick to pull together and a nostalgic hit for any costume party.
Step 1: Hair
First, brush out any tangles in your wig. It's important to keep in mind that the longer your wig is, the bigger a challenge it will be to prop up and walk around with. I hung mine upside down, and gave it a bit of a trim. Be sure to keep some of these scraps to cover the netting later on.
Once your wig's the desired length, dunk it in some glue. Elmers is fine. The hair on your wig is plastic, so don't bother with proper hair products - glue worked better. After you've fully saturated it, brush through again with the comb as best you can. Then hang up overnight to dry.
After the hair's dry, use your comb and tease the hair by brushing down towards the "root." This will add a lot of volume and cause a bit of "troll dandruff," but that's easy enough to shake out.
Step 2: Hair Insert and Assembly
Using a strong piece of cardboard (a side from a used box is totally fine) cut out two identical petal-type shapes. See my image for reference. Measure these pieces so the arch at the base rests comfortably on the top of your head.
On the tip of one petal, and the base of the other, cut out thin strips. Slide pieces into each other, so they cross into a pope-hat-shaped piece.
You might need a friend's help when inserting the piece into the wig, as I found it worked better when on your head vs. on the table. Tie at the top with a hair tie/ribbon. The messier the better!
Once tied up, you'll see that some of the netting is visible in the back of the wig. Depending on your hair, you might just want to bobby-pin the back of the wig up. Otherwise, take some of those leftover hair clippings and glue them to the back of the wig. Because they're so short, they should stay in place.
Step 3: Jewel
You'll want to get some holes in your plate, so you can easily sew it onto your leotard. After a couple failed encounters with different drills or hole-punches, I realized heat was my best option. I used a soldering iron to quickly melt 2 holes in my "jewel," one at the top, another at the bottom.
Once you have holes, it's time to add some color! Cut a bag open so it's a single layer. Then, using spray adhesive, apply a thin and even amount to the top of your jewel. Lay bag on top, and smooth out any bubbles. Repeat for a few layers. Then, using an exacto knife, cut off the edges.
Step 4: Assembly
For your body, you'll want to be covered, even though you're giving the illusion of being naked. I found some nude pantyhose that were "sheer to waist," meaning there is no change in thickness as you move up the thigh. For the leotard, I tried American Apparel, but had better luck at my local dance-supply store. I wanted a fully covering leotard with sleeves, and they had one that best-matched my skin tone and didn't show off too much skin. This is worth shopping around a bit until you find the best one.
Put on your leotard, and grab some fabric chalk. First mark where your belly button is. Then, using the chalk with the leotard still on, roughly mark where you want the top and bottom of your jewel to fall.
Take off the leotard, and place the jewel on once more. Mark the bottom and top again; you'll see there's a little bit of stretching when you put on the leotard, so be sure to account for this when sewing on the jewel. Taking a needle and thread, simply sew the two ends of your jewel onto the marked lines, leaving a little bit of slack.
And you're done! Throw the whole thing together, and go cause some troll-y mischief.