Once i cut my whole left hand with a sharp knife with hundreds of cuts, in both horizontal and vertical directions. It bleed pretty well, but i didn't achieved the result - blood loss.
So i never done this again. That day i was drunk and did this because my father beaten my head a lot, i didn't wanted to live. And you know for what he did that? For the fact that i started meeting with girls. He screamed at me, that all women are the same and i'l never achieve anything.
Usually i just beat my head myself. But you know, i realized i was getting dumber and it didn't helped in any way, so i stopped doing that too.
Now i just beat my legs, my thighs. It works pretty well for me to stop being sleepy or motivate myself to anything. Pain from bruises on thighs is somehow very pleasant.
And no anons, i don't recommend you to cut yourself. It never works. You will just have to wear long sleeves to hide cuts from everyone, and scars will never disappear.