How? Do you empty all your mind? What do you think about? Help!

If you stop breathing then you are doing it wrong.

That's true for almost every activity, except freediving, isn't it?

Yeah, a big can of big worms.

This analogy is surprisingly and unexpectedly? appropriate. Good one, Phoenix.

All this talk about not thinking, empty mind is only for the experts. You are not there yet.

Try this. I am being serious here. Close your eyes and 'see' a can. Then open this can and imagine all these worms wriggling uncontrollably out of it. You are in a state of anxiety, panic even. What do you do? Use you mind to slowly and calmly get them one-by-one back into the can and close the lid.

What do you feel now? Calmer, relaxed, mentally and emotionally more focused?

Repeat this exercise a few times for a few days.

Come back in a week and we can go on to the second lesson. Perhaps by then you will know what the second lesson is without my help.

Oh yes, I can see how the activity of dying could involve the stop breathing part without being labelled as wrongfully done.
In fact, one could almost go so far as to say that it isn't done 100% correctly, if it doesn't involve at least some degree of stop-breathing.
Therefore I stand corrected wouldn't surprise me if you were to come up with another breathless activity tomorrow, to really turn the knife in my wound... sob!

How to introspect yourself (without using sharp objects )?

This is the type of meditation that i use. I Tend to calm my breathing down and mantain as less as possible amounts of thoughts in my mind. If there is something that I want to think about i tend to think about it e.g. Problems i tend to mediate about and attempt to solve mentally.