Stian Gudmundsen Høiland:
I don't really understand how I am supposed to deal with sensations that lasts for a while. For example: further into the session my abdomnen falling would take quite a while and I didn't know wheter to note with a "faaaaaaaaaling" or "falling, falling, falling, falling".
I'm with Daniel on this one. Noting "faaaaaalling" might give the impression that there is one sensation that is lasting a while. But, in fact, it's just a chain of sense impressions, one following the other, which seem continuous - this is especially obvious in the A&P when you can start to notice things 20-40 times/second.
so, i would say, focus on the falling sensation, and every time you notice the sensation anew, even if it feels the same, note 'falling'. if it feels solid then note 'solidity', since that, too, is a sense impression. focus on the impermanence of the solid-seeming sensations and you'll break through it eventually.