I’ve tried belly bands and thunderwear. They are an option, but not a comfortable one. Comfort is extremely important for CCW because if it isn’t comfortable, you start coming up with excuses to not bother carrying. And since needing your concealed weapon is a once or twice in a lifetime event, its easy to convince yourself that it isn’t worth the trouble.
My best solution for the larger gun is a zippered day planner with built-in holster or a messenger bag with some books and a sewn-in holster. Bible covers are especially useful because no one wants to talk to a guy who is carrying a bible around. He might be looking for an excuse to talk! LOL.
My best and most comfortable setup by far is my S&W .380 in a pocket holster. It has a thumb snap that is easily popped and keeps things very handy when needed. Of course, it works well when wearing blue jeans but not much else.