I made this Homemade Wonder Woman Costume for my 21st birthday party (some years ago now, but anyway).

I put it together from
1) a red leotard that I already had (and still have)
2) aqua nylon lycra shorts that were my sister’s – she wore them under her gymnastics leotard, I think; I used a packet of silver stick-on stars from an office supplies store on the front and back of the pants
3) red low-heeled shoes, plus a pair or two of red knee-hi stockings to look like boots
4) silver sticky-backed book covering plastic, cut to size to be the bracelets
5) I made the belt, chest W and tiara from yellow satin-y lining fabric, closing the belt and tiara with Velcro, and hand stitched the chest W onto the leotard front
6) I hired a wig because my hair was short at the time.