Do you want a killer look this Halloween, without the hassle? Then this DIY Slasher costume idea is for you. All you need is fake blood, a bloody knife prop, and some closet stapes. Just grab a white t-shirt, then splatter the fake blood on the t-shirt and give it a tear or two. Throw on the t-shirt with a pair of jeans, grab your bloody knife prop, and you're ready to hit the Halloween party!