Excellent material from Craig Douglas.
▶ TIP NO. 1: There is no truly safe way to move through a home when there is a threat inside the home with you.
▶ TIP NO. 2: A structure is a 360-degree environment. Threats can come from any direction. Don't limit yourself to thinking your threat is around the corner you're at which you're looking or even on the same floor level as you. Your threat could be down the hall, behind you, at your feet hiding behind a couch, or up above you on a landing.
▶ TIP NO. 3: Learn to view your environment in terms of what you can't see. If you can see a threat, it is relatively easy to deal with. If you can't see it, that threat can be a bigger problem. Learn to look at edges, not holes. The opening of a door isn't as important a place to focus as the two side edges, from which a threat could emerge. Arguably, you could also be attacked from the top edge. This is important to remember as you move. Check many danger areas at once.
▶ TIP NO. 4: There are three potential planes of visual impediment— vertical, horizontal, diagonal. Vertical planes are corners and doorways. Horizontal planes are generally furniture and countertops or islands. Diagonal planes will almost always be stairways, in a home-defense scenario. Always seek distance from a plane of visual impediment.
You want to be as far away from these planes as you possibly can be to maximize your field of view beyond them.
▶ TIP NO. 5: Your "shooting platform" must conform to the plane of visual impediment. In order to maximize your safety through minimizing your exposure around corners, your stance must adapt so that you don't telegraph elbows, knees, and feet around corners before your eyes can see a threat. This also means you should train for shooting in a variety of unorthodox shooting positions, when you are at the range.
▶ TIP NO. 6: Pace your movements appropriately, to solve the problems or deal with exigent circumstances. Take as much time as possible to work angles and enter new danger areas. You want to see as much as you can before you commit to moving around a corner or exposing yourself to a new danger area. Of course, if the reason for your movement is the need to rescue a screaming child, you will need to pick up your pace.
▶ TIP NO. 7: When you are moving alone, you are always exposed in at least two directions. Unlike being in a fixed position with your "back against the wall," when you are moving, you must be open to attack from at least two directions. You cannot assume that your threat is definitely in front of your direction of travel.
▶ TIP NO. 8: Make every possible attempt to minimize multiple exposures. If you can, adjust your route through a structure to lower the number of doorways and corners you can see (and be seen from!) at any given moment.
When you are forced to be exposed in many directions, minimize the time of exposure by changing your pace. You can mitigate the deficiencies of moving alone to some extent by moving faster to specific points of relatively increased safety. Your positioning between fast movements must be planned and precise, as you move through a structure.
▶ TIP NO. 9: Minimize the angle of potential threat to 45 degrees whenever possible. If you can put your most significant danger areas within a 45-degree cone, it is more plausible that you will pick up movement from a threat in time to respond before an attack. The wider your potential area of responsibility, the less likely you are to be looking in the right place at the right time.
▶ TIP NO. 10: If an intruder is encountered, be prepared for anything they might do. They may attack, they may flee, they may engage in dialogue. These kinds of problems are very mercurial, and the human factor must be accounted for— this is not a video game.
More to learn, but never stop learning.