It's easy and fun to spend an afternoon in the lower 40 or at the target range. It's also a good way to sight in your weapons and get familiar with them. It's not the best way to prepare for firearms self-defense, however; for this you need to practice more realistic scenarios...
When There's No Bench
Bench shooting is fun, but it's not realistic in terms of defending yourself or your property. For this, you need quick reaction times, good instincts, and practice shooting from a variety of positions and stances. Should you be accosted by an intruder in your home or by an assailant while jogging or walking to your parked car, you'll need to be familiar with shooting under less-than-ideal conditions.
Dry Fire Practice
This is a favorite exercise of mine that can be done anywhere in your home. Remove the magazine from your pistol or rifle, and clear the chamber. Now you can watch the evening news in style, drawing a bead on the FBI's Most Wanted or other undesirable characters appearing on the screen. Learn to draw a bead quickly and accurately; dry firing your weapon will also help build up the muscles in your hand that are used in actual weapons firing.
Some New Views of Your Target
You may not always be sitting or standing directly in front of your intended target. If accosted by an intruder, you may be in a prone position and half-asleep. Do more dry-fire practice from your bed, spotting an imaginary target in the doorway or window. Hang some small targets on the front door and living room windows; lie on the sofa and pretend an intruder has just broken through a door or window and see how long it takes you to get the target in your sights. Practice the same techniques from a half-sitting, kneeling, or half-prone position as well. Step behind a wall to an adjacent room and practice drawing down on the targets you've hung for practice. Practice dropping your magazine and reloading without looking down - the forward surface of a magazine is easily differentiated from the rearward surface by touch.
Now, head outside to your backyard or target range, and practice these techniques in an outdoor setting, using the corner of buildings, trees, brush and other obstructions to perfect your aim from a variety of positions. Remember that an assailant may try to knock you down before mugging you (or worse), so learn to draw and aim your pistol or bring your rifle into firing position from a number of awkward positions on the ground. Stand up and walk at different speeds in different directions while maintaining the target in your sights. There's no substitute for practice, especially when it comes to realistic self-defense scenarios, so get out and do it! I'd rather have the neighbors think I looked ridiculous than to be the victim of a crime simply because I didn't know how to get a target in my sights in different circumstances.
Live Fire Exercises
This is fun once you get used to having bullets hit next to you rather than 50-100 yards away! The first step is to position yourself about 10 feet to either side of a target. Have an experienced shooter (one you trust, with good aim and a sighted-in weapon) fire at the target and listen to the sounds of the target being hit generally followed by the sound of the weapon discharge. Weapons of differing style and caliber have distinctive sound patterns which you should commit to memory.
Follow the direction of the sound when the round impacts the target - turn your head toward the sound rather than the target or the shooter, and note where the shooter is in relation to where you're looking. This can help you locate an assailant by sound as well as visually. Have the shooter fire a number of rounds until you can stand and listen without flinching.
Imagine there is incoming fire and hone your actions and reactions for optimum survivability! Spot a target anywhere from 25 to 100 yards away. At the sound of this imaginary incoming fire, drop quickly to your knees and then to a prone position, keeping your weapon in firing position. Roll first to one side and then to the other still maintaining a firing position and view by extending your arms and holding your weapon steady. Drop your magazine and reload while prone, maintaining as much movement as possible. If you draw real incoming fire, you won't be static! I skinned my knees up first time out on this one, but learned a valuable lesson about keeping my target in the sights.
Chances are your target won't be static and standing in a huge open field. A clear field of vision is a great thing but you may not always have the option, especially in a major disaster situation. If you have the misfortune to find yourself in the middle of a riot, there will be a lot of activity, noise and probably smoke at the scene. You can practice shooting in such conditions by sighting in a target, then having someone light a smoky fire (use green twigs) between you and your target - if you have access to flash-bangs and smoke grenades, you can really have fun with this. The important thing is to note the initial position of your target and follow any movement by sound or glimpses through the smoke. You can simulate movement by tying your target on a pulley-line and having someone reel it in either direction while you shoot. You need to get into the habit of shooting at moving objects as well as stationary ones.
Hopefully you'll never be in the position of taking incoming fire, but should you find yourself in this unfortunate position, practicing the above techniques can help you come out on the winning end of this survival challenge!