Point shooting using a body index can loosely be defined as shooting the pistol using any position that is not placing the pistol in line with the eye and target.
Many point shooting advocates teach their students to use their peripheral vision to see the top of the pistol slide while lining up on the target. The major problem with this is that almost all people in gunfights report experiencing tunnel vision. That means your peripheral vision is not there. By training to use peripheral vision one is training to do something that will be almost impossible in a real gunfight.
Body index is actually harder to learn than just using the flash front sight method. Flash front sight is placing the front sight in your line of sight and on the target before pressing the trigger. It is much quicker to learn to shoot this way and the calibration is much finer than point shooting. Flash front sight does use the same kinesthetic awareness as point shooting without having such a degree of missing.
Body index is just as hard if not harder to learn while moving than learning to use the front sight. Gaining the body angles needed to properly point shoot is difficult in a dynamic situation. Body index is even more difficult to learn while the target is moving at the same time you are moving.
Retention shooting is keeping the pistol close to the body while within arms reach of a subject. You should know how to do this. Go slow at first because you might end up shooting yourself if you don’t. The reason I suggest limiting retention shooting within arms reach of the bad guy is that same tunnel vision makes telling distance very difficult to impossible for many shooters. Many police officer report being a yard or two away when they were in fact three to seven yards away.
When grappling with a bad guy retention shooting will save your life. But don’t overestimate the need for retention shooting. Police officers use it from time to time but not as much as you might think. You might need it as a civilian during a car jacking, rape attempt or if you went looking for someone and got into a wrestling match with them. If you learn to draw, sidestep and move at the same time (even in a car) you will almost always gain the room needed to shoot two-handed at full extension.