Sliced Finger :)

First attempt... so it's not that good, but it still looks gross :D Next time i would add more black in the cut to make it look deeper :-)
I used this:

Cut skin :D

Use black eyeliner to draw the lines and then go over with cake blood/fake blood :D
I dipped a stipple sponge in cake blood and went over the writing in the first picture, it looks more splattered :)