Start by studying the chart above and learning to not do any of those things. Blading your body, readjusting the weapon, printing through clothing, not being conscious of how the gun moves when you move, etc. All things that will go unnoticed by the casual observer but can often be picked up on by the trained eye. I’ll try to find some good links for you and post them up on a reply here tomorrow. There’s a lot that goes into it, from gun and holster choice, body type, clothing choice, behavioral patterns etc. A lot of it can be learned by just wearing your weapon around the house and getting used to the way it feels and moves on your body. I did that for a few weeks when I first started carrying, it helps tremendously.