dont wear your tie/collar too tight
i almost choked in my interview because my shirt collar was a tad bit too small - probably turned purple, in addition to looking awfully weird, as every time the interviewer turned away I tried to loosen it as much as possible - felt like my eyes were popping out too :-\
maybe there was a hint in the fact it took me about 10 tries to button it
hope this saves anybody else embarrasment and/or a near death experience