For my homemade Poison Ivy Costume, I used a green leotard, solid black leggings, green fish nets, two red clip in hair, boots, then rap a vine around your complete and easy poison ivy costume.
I got a white leotard because I couldnt find a green one and dyed it with Rit Hunter Green for my main body peice. Then I dyed my hair red to match her long red hair but had two red clips that stick out brighter then my hair just like the cartoon. I took regular black leggings and overlapped green fish nets on my legs then used just some black boots and a fake green vine from the craft store and bendable wire to make it rap around my shoulder and down to my leg. As far as make-up I took black eye liner and drawed and little out from my eye and dabbed some green eye shadow as a little shine to the eyes. The brightest red lipstick and I became Posion Ivy!