I tested partial a while ago. There was a blog in which some guy gave some tips for it. I made a hangman's noose and put a shirt under as padding. As the guy suggested, I placed the knot in front of the neck. I just let some of my body weight put some tension in the rope and it got really tight around my neck. I felt my mind go numb instantly. My vision was fading and I felt no head pressure. I suppose I successfully compressed the carotid arteries. Great thing was it wasn't painful and I felt no suffocation. I did not plan to die that day so I did everything I could in that spare couple of seconds I had to get the knot loose around my neck and let some blood in my brain. Even if I went through with it, I could have been found fast easily so yeah it really was not the perfect moment to ctb. Somehow I managed to get the hangman's knot loose to let some blood in but believe me it is VERY HARD to do so.
In retrospective I really do not recommend it because I think there is a concerning chance of surviving and getting brain damage. Also, I feel like partial is way to risky. Most work to get you on the bus is done while you are unconscious and it takes a while. If the rope snaps you might come back, just not fully...