What is one accessory you wear in formal or semi-formal dress (think lapel pin, piece of jewelry, writing instrument etc) that has particular sentimental value or a good story behind it?

I picked up a chocolate brown suit, does the burgundy shirt work with it? The mustardy one does as they’re in the same tonal range. Everything’s a bit darker than in the photos, but I can’t get the adjustment to look quite right so these are unedited.

I'm not going to theaters really often, but I'm planning to go to the Musical I like with a girl that I like. I need advice what should I wear in that situation to look casual, but not like a bum.