Hair, fishing line, field grass etc etc covered in a mix of tamiya clear red and black/blue paint.
Makes perfect blood.
My method is to stick some double sided tape on the edge of my shelf.
Stick hairs etc to this and then dip the hair into a pot of the blood mix.
Pull the hair out of the pot and leave to dry. This will give you a nice drip on the end. Repeat as many times as needed to increase drip size.
Here
Nigel