Mandi Hang_Me said:
based on experience..it happens very quickly...never do it alone.
This is very true. I would advise against ever "trying any of this at home". Unconsciousness occurs very quickly and if you are alone YOU WILL DIE.
Of course if you want to die that is another thing. Hanging is a very effective way to commit suicide. All you have to do is have a rope strong enough to hold your weight and a way to suspend yourself. Once suspended unconsciousness will occur in very few seconds and death is assured in 10 to 20 minutes.