There is no time when I am more conservative in my dress than when I am presenting a case to a jury. Some lawyers wear the exact same suit and tie every day of a trial on the theory that wardrobe changes would distract the jurors. I have more faith than that but nevertheless wear a dark suit, subdued tie, and oxford shoes. It is a matter not only of respect for the jury but also of self-confidence.
Shameless plug for the legal system: other than voting and giving unlimited sums of cash to political candidates, jury service is one of the few ways we can participate directly in the political system. Smart jurors are essential to justice. If you think juries are out of control (and I assure you that they are not), the best thing you can do is to appear when summoned for jury service.