Good for you! It's great you learned about a clipping mask! I use them in every sig just because they are freaking amazing :P.

The trick to them is to keep them bigger but in small number. So i usually have atleast like 3-5 but they are pretty big ones.

try to remember to either mask out/erase the splatter that get not the renders face, because that's plain distracting away from the render. Nice job though on learning it.