Cut some crackers, both sweet and salted, in small rectangles. Smear, in the center of each of the sweet ones, a little of frosting to create the small piece of gauze. Try to straighten the sides as much as possible using a knife’s no cutting edge. The more you work on it, the more your gauze will look rectangular. After that squeeze the gel food colour creating the blood stain. For the remaining ones follow the same procedure, but this time cut small rectangles from the cheese slices and use ketchup as blood.