Severed appendages are one of the many staples of the horror genre.
If you're making a gory slasher flick, it'd do your production good to know a little bit about how to make a few things from scratch: 1.) really good fake blood, and 2.) realistic body parts. In celebration of this spooky time of year, Indy Mogul's Erik Beck shows you how to make a very realistic fake hand prop, complete with exposed bones, flesh, and blood that oozes from within, out of alginate, silicone, wooden dowels, and of course, a bunch of ingredients that make up a killer fake blood recipe.
Admittedly, this tutorial is geared more toward experienced special effects artists, but Beck provides enough information and explanation that it seems as though anybody with a desire to add to their skill set can pull it off (maybe after a bit of fumbling around).
Now, obtaining and mixing together the materials is relatively straightforward, but the step you might want to really pay attention to is painting the prop once it's been molded. Since the whole idea behind this tutorial is creating a realistic fake hand, not painting it properly may leave you with a prop that doesn't sell the illusion.
If you're not a great artist, though, there are ways to mask your less than stellar painting skills using classic horror conventions, like low light, shooting handheld, or just dumping a ton of fake blood on the thing—though the low light idea might actually serve you best.