When we talk about concealment in the firearms industry, often we focus on covering the gun in the most effective way. While this is a large component of concealment, it is not the end of it. Concealment of your tools, but also your abilities and intentions are also very important.
Lets start by addressing the gun itself. We do need to conceal our defensive handgun, because it is important to ensure that we have the element of surprise, but also that we understand the social implications of being found out that you have a firearm. If you are in law enforcement or the military, someone having a gun is mostly a non issue. However, if your setting is a professional office, care center or retail outlet, the consequences can include termination from your job. This creates issues in selection of equipment. If you need deeper concealment, sometimes it affects the firearm you carry, or the holster you use. Sometimes, you may need to compromise speed of access in favor of covert carry to preserve your concealment. All of these factors come into play.
Next, we get into the concealment of our abilities. Some may think that people knowing that you are skilled will be a deterrent to violent attacks. Perhaps this has some truth, but it also means that the high level predators will simply change tactics to ensure their win. If you walk around with a gun or fight gym branded shirt, or a patriot branded "bad-ass" shirt, you may very well be selected based on the potential value you carry with you (your gun). Higher order criminals may then no longer use direct fear and intimidation tactics, as it presents too much risk. They may opt for an ambush, taking you with overwhelming violence before you can react. Concealment of abilities means that you did not show your hand when it comes to how prepared you are to defend yourself. If someone knows what you can do, they can plan accordingly. It is far better to allow your attacker to find out that you are a Golden Gloves boxer and a concealed carrier after they think they have the upper hand. At this point, you have the ability to use your skills without an active plan of resistance (the Jiu Jitsu choke is always easier when someone doesn't expect it right?).
Please keep your concealment effective and make sure that you have abilities beyond what your attacker believes.