Make sure that ALL doors to the outside are metal or solid, 1 3/4" hardwood and ALL have good, sturdy locks.
Use the locks you have. Always lock up your home when you go out, even if it's only for a few minutes.
Secure sliding glass doors with commercially available bars or locks, or put a wooden dowel or broomstick in the door track.
Make sure your windows, especially at ground level, have good locks, and use them.
Make sure all porches and other possible entrances are well-lit.
Don't hide your house keys under the doormat or in a flowerpot. It's much wiser to give an extra key to a trusted neighbor.
Keep written records of all furniture, jewelry, and electronic products. If possible, keep these records in a safe deposit box, fireproof safe, or other secure place. Take pictures or a video, and keep purchase information and serial numbers if available. These help law enforcement agencies track recovered items.
Clearly display your house number, so police and other emergency vehicles can find your home quickly. (This is so important, it is required by Kalamazoo Township Ordinance.)
If you see a screen that has been cut, broken windows, or a door that's been left open, don't go in. Call the police from a safe location.
If you hear a noise that sounds like someone breaking in or moving around, quietly call the police. If you can leave safely, do so. Otherwise, lock yourself in the room you are in and keep quiet.
Think carefully before buying a firearm for protection. Guns can be captured and used on you or the police, or they can be stolen and sold to anyone. In fact, firearms are so sought after that someone could break into your home for the sole intent of stealing a gun. If you do own a gun, keep it locked up, with the ammunition secured separately, and learn how to use it safely.