Costume: make-up.

Make-up is a significant part of costume, which creates the right impression for the character.

Our female character - is a victim of domestic violence, so her make-up will include something like bruises on the eye and hands and maybe a cut on a cheek or lip.

For him, as he is the abuser, nothing like that, but an open wound on the belly, because she stabbed him.

Female make-up:

Analysing everything I've read, I think creating a 'black eye' bruise is relatively simple:

-First of all, you have to 'place the bruise' and draw a shape line. 

-Then start filling it up with a mixture of red and dark blue eye shadows.

-Mix two eyeshadows until you get nice purple colour under your eye.

-Lastly, add on some black eye shadow in the middle to add 'depth'.

READY!

Of course, there are many different techniques of making bruises. For some, you might not even use eye shadows, or you might use other colours - I just find the process I've described above the most easy and fast. But that might not be what we'll need for our thriller - depends on whether it will look good in the shot or not, and what parts of our actress' body we choose to cover with bruises. Also, I feel like eye shadow are shining too much when you apply it to the face like that, but that's not what we want, because the real bruise don't shine.

e.g a completely different bruise - with the use of  red, orange and yellow eye shadows, no blue or black used at all.

The same technique may be used for making bruises on her hands - for that purpose eye shadow technique will suit quite well, because eye shadows wouldn't look as shiny and bright.

Male make-up:

With male character it's much more easier. The only make-up he needs is a knife stab.
Making a knife stab turns out to be relatively easy:

Especially, if we don't use the actual knife sticking out of the wound - because we need him to crawl on the floor when he wakes up and it becomes a bit of the problem when you have a knife in your belly + removing it in the shot would be too bloody.

Anyway, so for the male character, all we have to do is:

-Cut a white shirt somewhere near the belly.

-Put a sponge soaking with blood under it, so it squeezes blood when you press on it. This would look realistic in the shot.

AND ITS DONE!