1) Wear IWB holster while being fitted for suit or slacks,better fit=more comfort and better concealment.
2) Wear belly-band rig high on body almost under arm,then cover with a big dress shirt tucked in. I had one of the buttons on the dress shirt removed then sewn on the front placket. Sew velcro strips on the inside to keep shirt closed where button was taken off. Seperate velcro with hand reach inside grab pistol and your in business. Not the quickest but comfortable and low profile.
3) While wearing a suit place a lapel pin on opposite side of the gun,it draws people's attention away from the bulge under your jacket.
4) Wear military shirt stays (they attach to the bottom of your shirt and then to the top of your socks).Keeps your shirt tucked in especially when carrying IWB.