I think when it comes to Bellatrix's costume the first place to check out is ebay or charity shops. Her ensemble is, of course, all black with rips, tears and is totally falling apart-reflecting the insane, sinful character that she is.
Many fancy dress sites stock her costume for about £25-£50 but I often think a home-made one is much cooler!
You need a black gypsy skirt which is full length, a black corset, a black long-sleeved top and some black shoe laces or black ribbon, if you're up for some sewing grab some black lace too in order to create a skirt overlay. Simply cut the sleeves of the top and intertwine the laces then re-attach to the shoulder, you can also cut along the seam down the arm and do the same.
Hair, Face & Nails
Bellatrix has one crazy-ass hairstyle going on, curling tongs are required with some serious back-combing and a spray of white hair colour to showcase the greying in Bellatrixs' hair.
Make-up is key here, Bellatrix has dark eyes both in colour and surrounding, defined cheekbones
Make-up wise you need a pale foundation, a mix of brown shadows that can be used for contouring as well as darkening around the eyes and this affordable eye-shadow palette By Little Mix is perfect to create the dark, sallow look of Bellatrix. I have even found an awesome tutorial online by Michelle Phan, check it out here
As for her nails, all you need is a bit of chipped nail polish and to dirty them up to create the grubby, disheveled Bellatrix Lestrange look.
Shoes, Jewelry & Finishing touches