Well hangovers can easily be prevented as long as you didn't black out. You just don't forget to drink tea before sleeping, and in extreme situations you may pop a paracetamol pill or two.
But regardless of whether I have tea or a pill, or nothing at all, the technique is to keep seated on the bed before lying down. And when lying down, the pillows have to be propped up so that my head is higher than my chest. If I do this it's guaranteed i don't have a hangover.
Of course, the feeling of toxins and a little numbness will still be there, but your head is clear.