the more you do street photography, the more it just becomes a natural thing... i think when Dick says more aggressive, he doesnt mean in a "knock you down" sort of way, but more of a "i want this picture" sort of way... street photography is a lot of fun, especially when you get away from the fear behind it
also just in looking at dicks site, his style of street photography is much different than the style i'm talking about... his are portraits, where he clearly has asked the people to stop so he could take the photo... they are great photos by the way... the style i have been talking about is more of the Bruce Gilden style.. unsuspecting, spur of the moment shots.. candids, where the people were just doing their thing