Hmmm.

I think at the beginning you switch strongly between different Foci, as you are trying to hit the "trance band" on the way from waking to sleep at all. Later on you can find more specific states or Foci in this band and associate them with certain phenomena.

Phenomena start to come step by step the deeper you travel Focus by Focus.

Hemispheric Synchronisation, all-body drowsiness, the beginning of a detached and floaty state, time slowing. These are the phenomena that I would expect between Foci 10 and 15.

Hope this helps a bit.

Oliver