If your going to dress well, don't cop out by "casualizing" everything about it. If you wear a tie, close your collar and push it up; if you wear a proper shirt, tuck it in; if you wear a jacket, button it. After all, if something like this:
...can be done with all the finer points of neatness in place, what's your excuse for half stepping? And who says that wearing a suit is stiff and restrictive? Someone without style, no doubt.