stacyrox - p. sub potency varies greatly from mushroom to mushroom and batch to batch...
my first of last years season were 4 small/medium specimens, and i tripped VERY hard, my friend had a couple more than me that night and only tripped mildly. further consumption indicated that on average, 10 small/medium specimens from our patch resulted in a fairly strong experience. of course, the variation in potency can be surprising, especially when you might be hardly feeling anything from X mushrooms, and then after consuming one more, are propelled into outer space.
so, the best way to dose would probably be to powder up an entire batch and devour them someway from there - perhaps make measured doses mixed with chocolate or honey.
and even then... mushroom dosages are almost exponential in effects, so dosing is always quite difficult. a 3 gram cubensis trip would most likely give someone a reasonably strong trip, however a 4 or 5 gram trip on the same mushrooms would be much much different.