I have recently discovered Blood Magic. I didn't discover it LOL I happened upon it. I t is working so well for me so far. When ever I do a spell that has any way shape or form of a desire I use this. I always write down what I want as if it has already occured. I draw a small pentagram with a circle around it. then I prick my finger and smear a drop of my blood around in the circle.(I used a diabetic finger sticker. Please always use safety and never share. You can die from blood born illnesses.) Then I fold the paper three times and Burn, Bury Bag or what ever else I was going to do with the paper. It has been working very well.
I as well use blood as an offering. Blood is a very good manifestation base. Whether its the blood of an animal or of yourself, as the blood drops on the floor, sigil, fetish item, etc, it releases vapors as it cools thus making it a potent base for spirits to manifest. Many people are disgusted at the idea of animal sacrifice, I myself dont use animal sacrifice very often, though it does have its place in ritual/ceremonial & chaos Magick. The greatest sacrifice & offering a magician can give is of him/herself. Ive found that the offering of ones own blood is far more potent than an animal sacrifice.