There were times, many years ago, when we did not have to worry about security. Unlocked doors were very common. Times have changed and we now have to lock up everything.
Dead bolts are the most secure lock for the front door. The newest deadbolt out is a bump-proof lock. Very hard to pick. Don't buy cheap on this lock. Look for a strong latch pin. Purchase a hardened center core or titian with a 1" or more in length. Locks are sold by turns (which means 1 turn is when you open the door) and good, better and best. Best is a six-tumbler lock making it hard to pick. While cheaper locks have 5 tumblers they are easy to pick. You're best also has a non-tarnish finish so it will not fade or discolor.
Locking security while you are inside a chain lock lets you open the door enough to see who's there before you open the door completely. A simple hinge swing latch mounted higher up on the door from the dead bolt lock is a very secure lock. This lock also can keep small children inside as well as elderly people in that don't need to be out. There are also devices that set off an alarm when opened.
Peepholes are placed in the door and let you look to see who's out side before you open the door. Always install the 180-degree peephole. Helps you to see someone who might be standing off to the side of the door.
Can be handled the same as the front door for locking. Most of the time a break in is at the back door. Sometimes we fail to secure this door. It is just as important as the front door to secure.
If your locks are not working on your door get an under the door wedge bar to use until you get your door lock fixed. This bar slips under the doorknob and extends to the floor so it won't let the door open. When traveling this bar can be used to give you more security in motels.
Patio doors are also an easy break in and there are several ways to secure them. If both doors slide there are pins you can buy. You drill a hole where the doors overlap. Drill through the first door and part way through the next door and slip the pin into the hole and neither door will slide. If only one door slides there is a drop down bar that fastens to the door jam and drops down to lock and keep the door from sliding. When the bar is not in use the bar locks up out of the way. This bar is installed at the middle of the door.
There are a lot of patio door locks that fasten over the bottom track to keep the doors from sliding, some you use a key to unlock and some don't. Or just use the broom handle in the track. It is not the best way but works in a pinch.
Do not leave your garage door open while you are not in the garage. They might not have time to steal anything at that time but if they have the same garage door opener as you do it only takes a few seconds to get your code on their remote and come back later to get what they want.
When replacing a screen use aluminum screening. When aluminum screen is cut for entry you can hear it all over the house. Fiberglass screen can be burned with a cigarette. Some of the old wooden windows have been nailed shut for security. This is not a good idea, as you may need to open the window to escape in case of an emergency. There are a lot of different kinds of locks for the top of the window to secure the window. There is also a vertical lock you can mount on the side to let your window open to only 6 inches or whatever you prefer the opening to be.
If you sleep upstairs be sure you have a rope or chain escape ladder to get out. It is also best to have a small ball bat or large heavy stick in case you cannot get the window open. Always have a plan to escape in case of fire.
Put plenty of motion lights up so if someone enters the yard the lights will turn on. An intruder does not like lights. Also, it is good for when entering the yard yourself as it lets you see if anyone is in the yard.