[quote=(D Z) Dhru Val]
A TACK:
Some q's - In Dan's book he mentions tuning in to sensation at a rate of 1 to 10 per second, this i can do with breath in nostrils, in fact it's harder at this point to perceive breath as solid for concentration practice. However when i try and note each part of the breath sensation as rising/falling it really slows things down. I can easily observe the quick sensations of each part of the breath but to then apply a note them just seems clunky. Surely in applying the note you are not aware of as many sensations because of the time taken to apply the note? or is the fact that i have observed the sensation enough - i.e no further note needs to be applied?
You can apply a single syllable note like 'ba', 'da', 'fa' etc. This keeps your verbal thought processes busy, and also serves as a pace setter for refreshing your observation.
If your concentration is very strong, and you are not distracted by discursive thoughts then it might be less important to note.
A TACK:
Also - with regards to the 3 characteristics, is the very fact that one is observing/noting every small aspect of breath in itself investigating the 3 characteristics? e.g seeing impermanence in every small aspect of the breath - or am i not getting it and investigation of 3 characteristics needs to be applied in other ways?
Probably best to investigate it one characteristic at a time.
Starting with impermanence. Soon you will get the rapid tingly sensations happening and cross AP.
AP will lead to the dukkha nanas, so then investigate dukkha and the impermanence of dukkha.
Once you understand the impermanence of dukkha you will develop equanimity. Then stop noting, but continue to be alert.
Start to look for any sensations that your mind has subconsciously associated to be 'self' or 'observer'. Investigate no-self here.
Be relentless and get stream entry.
Thanks Dhru Val - certainly in day to day life i will note some things when concentration lapses or just to keep me focused while i'm doing something. However i can clearly feel things like the wind/air at the same time in many parts of my body at once and i'm mostly clearly aware of this and able to watch how it changes etc, but i can see how in other situations the noting would be useful.
The next part of your post almost knocked me off my chair...
Over the last few weeks I tingle/urge to itch but not quite, really heavily during practice. I might sit for an hour in the AM and similar in the PM and every time i sit the tingling starts. I have been taking a new medicine around the same time as I practice, and i thought the tingling might have even been a reaction to my new medicine - even went and saw my GP

Doing an N1 and practicing at other times independent of the meds i now see that practice is the trigger.
Specifically seems to come on as soon an access concentration comes on line and intensifies with priti.
Over the last few days access concentration is almost instant, tingling and pritti more intense than ever. tonight i sat for an hour and really broke down the sensations of the breath, tons of vibrations/pulses as expected, Priti starting about 5 mins in and became extremely intense as vibrations sped up, or ability to observe them. Then something happened after about 30 mins - almost like the brain had an overload (but it didn't feel this way) heart rate shot up, my eyes just flew open (although lately they feel like they want to open whenever i sit), was more intense than anything i've ever felt before in practice. Then bought myself back by solidifying the breath and doing concentration for the rest of the sit. Jhanic state i got in to then was extremely spacious.
I was in the shower yesterday and had a "reality drop out moment" and then i suppose some insight - the feeling/knowing that i'm really just a bag of sensations experiencing a selection of sensations out of an infinite number of sensations happening at the same time. I guess this is no self stuff? have had the feeling over the last few days of awareness hugely intensifying overall, and especially of mental sensations, and them really being given no more weight than other sensations, noticing how quickly they rise and fall like other sensations. I htink there has been a shift.
Apologies for the rambling post, but feels good to write this stuff down

does this experience sound A&P esque? For me i think this is important, because although interesting, the physical intensity of what happened today during practice and seizure like pritti is intense. Be good to know where I might be now on the map before i venture off in to formal insight territory.
Thank you
Aaron