For me, I need a t-shirt and at least another light loose shirt on top to assure not printing, or a single heavier garment (hoodie, jacket, etc). I know folks who waist carry with just a t-shirt and it works, but I've grown accustomed to hip carry and, while I am not worried about shooting myself, I just cant bring myself to carry where the gun is pointed to a femoral artery or other 'vital' parts. So I don't mind the extra layer.
You have considered your options. :)
There are actual pocket carry pistols.