Thank you, Sri. You have confirmed my suspicions. I guess my problem is that I want to make the best use of the music, and so plunge right in. I think as far as ballroom goes, I'm probably a good leader, and for instance, in the Quickstep, as you hint, the best thing is to take a step (which in my opinion need not be small) on the left foot before you start the basic (oh, I'm talking International style). If the girl is counting, then she may figure that I'm going to start off on a left (I tend to dance with partners I already know - possibly not the best habit). This first step would be taken on the second beat of the bar, where you count two beats to each bar of music. Of course, in Quickstep, not all steps finish on an even number of beats, so this becomes ambiguous as you keep dancing, and again, is just convention rather than the "correct" thing to do, even though it feels right.
For the benefit of anyone else looking at this discussion: One important thing to do when leading into a dance is to start moving well before the beat you intend to start on, falls, and if you start stepping forward, then you must make sure your body moves before your feet do, otherwise you may kick your partner.
Once started, in ballroom dance you would always keep your weight approximately between your feet, to form an isosceles triangle between your two legs as the equal sides and the floor.
Body contact helps