Begin with a tissue. Place small pieces of it on the area you want to make your cut wound. Then cut it wherever you want.
Step 2: Applying color
Decide where your cuts shall be and color them using an eyeliner. I wanted three cuts, you can make even more, of course... :D
Step 3: Veins
In order to make it look realistic, I drew veins with eyeliner... (a blue one). Then I used a little bit make up foundation to cover them but, of course, not totally! :D
Step 4: Applying blood
Finally, apply red nail polish on your cuts. It shall be enough, but if you want you can drag the nail polish with eg a knife before it dries... A fantastic trick, isn't it! Here you go! You just finished your cut wound, hope you like it!