Tutorials/Shelter defense

Non- explosive resistant houses
If your house isn't made of one, you should always have a Moat, Man Made Lake, or something of that sort around your shelter to protect from creepers.

Other houses
You should have many windows, so as to be aware of any Mobs around. Light your houses and surrounding area well! It is suggested to have a Automatic Door or Minefield surrounding your house.

Security
It can come in handy if you have some security systems up. Here are some ideas:

•	Alarm, to make a alarm you will need: at least 1 pressure plate, a lot of redstone dust, and at least 1 note block. First put pressure plate(s) around the location you manly go, try to keep them separated as much as possible (optional). Then put the note block(s) inside your location and attach the note block(s) to the pressure plate(s) with redstone wire and you are done so whenever a mob or a player walks on a pressure plate then the note block(s) will make you aware of it.