I have been noticing a lot of confusion as to how to best type yourself. It seems to me that too many people concentrate on what is their dominant function.
Yet a Socionics type is more than a dominant function and, as Rocky pointed out, sometimes you take some characteristics of your dominant function so much for granted that you end up not even recognizing it.
So, I would suggest again the following approach:
1) try to recognize which Quadra you belong to. This can be helped by Rick's decriptions as in here: http://www.socionics.us/theory/quadras.shtml
Mainly, it's about recognizing the preferences of your weaker functions. For instance, for a Thinking type it may be easier to recognize whether you are Fe > Fi or Fi > Fe, rather than your Te or Ti preference.
2) Having found your quadra, it should be easier to see which types you are or not.
I think that getting deeper and deeper into precise descriptions of functions and dichotomies is not the way to go.