Full size 1911s are tough to conceal because of the long grip and sharp corner on the grip - it tends to stick out and print on your cover garment, especially if you bend forward.
I think the best way to mitigate this grip problem is to use a 1911 with an officer's length grip and a holster that cants the gun forward. One of the "bobtail" grip treatments on a regular length grip will also help. I personally favor a short barrel 1911 with an officer's grip, such as the Colt Defender. I find this easy to conceal in a high riding Kramer holster with a cover garment worn outside the belt, such as a sweater, sweatshirt or t shirt. I don't have any printing problems with the setup shown below: