Unless you are entering buildings with metal detectors or subject to search the key word is DISCRETE.
Discrete and LOW KEY are the watch words here.
For instance, don't use a Marine Ka-Bar to open your mail. That's quite an example, I know, but some guys will use any excuse to pull out a "dramatic" piece of their gear. Don't do it.
I carry more than one Swiss Army and more than one lockblade on my person, usually. I use the smallest blade that will get the job done, if I have to use a blade at all. If I can tear an envelope open with a pen, I will. I try to use scissors most of the time.
Once I was breaking down some very heavy cardboard boxes with my Spyderco Dragonfly. Of course, one of the guys sees it, gets all excited, and asks, from across the room, no less, "Hey, could you KILL someone with that?!"
Yep. A total idiot. And the boss was in the area, but fortunately preoccupied. Later on, the same guy asks me to show his buddy my knife. I said no. He said, very defensively, why not? "Because I'm not carrying it anymore, trying to lighten my load," I replied. I had it, but I was damned if I was going to parade it around the room. I totally punctured his balloon. I was very happy.
Now, when there's heavy breaking down to do, I don't plunge right in, and I don't volunteer, either. Other people do. Let them struggle with the dull kitchen knives. No, they don't carry pocket knives. I don't bother asking why anymore, either.
I have what I have and I keep mum about it.
-- Craig