Not sure about clocking other transpeeps. When I see one, I just smile a little bit! The closest to "clocking" another trans person I ever got (after discovering myself and everything) was trying to determine whether someone is trans or not, which can often times make me cock my head and stare a bit -- in the nicest way possible I guess lol. I mean, despite my excellent gaydar and transreceiver, I just can NOT discern for the life of me with some people. Been trying to determine if someone I know is trans or not for a while now... and if he is, he passes SO damn well that it really makes me think he's not. And if he's not... I'm afraid to ask, because I don't want to hurt anyone's feelings. >.<
As for my "trans sense", yes, I can definitely relate to that. I've experienced this often, as I can just tell... it makes me feel bad sometimes, like I'm judgemental or something, but it's probably just because I'm like that too and as a result I know what to look for? Not sure if that explains it. It's one of those things that you just "do" instead of trying ot really having to think about it.