In order to demonstrate the Blood Splash stencil, let's start with the lettering "Bloody Airbrush".
First I'll think about where to position the stencil. Then I'll spray an upwards running shadow onto the lower edge with diluted gray.
Next I'll move the template a bit to the left, put it on top of the previous spraying result and add a bit of red. I'll leave a bit of space so that the effect will become more visible.
I'll do the same with the other blood splash patterns on the Mylar sheet and I'll try to obtain a good distribution of splashes around the lettering. In the centre of each splash I'll spray the paint relatively thin. This makes the splashes look more realistic.
With an eraser pencil I'll remove about 70 % of the color on the upper edge of each blood splash in order to indicate a slight reflection.
Then, I'll remove it completely with an electric eraser, so that the reflection becomes even more powerful.
For the last step, I'll use a black crayon on the lower edges of the blood splashes in order to soften the hard edges of the spraying a bit. This way, the splashes are visually connected with the surface and don't look like they're simply stuck on.
Here you can see the finished blood splashes. Of course you can use the Blood Splash stencil not only for "blood", but for splashes of any kind and color.