This will be a tutorial on how to make a base for the nether, with two lines of defense and an obsidian-lined panic room to hide from ghast attacks.
WARNING! I will not be giving exact amounts of materials needed so please figure it out for yourself:)
Step 1: Basic Stuff
So if you are going into the nether you should have iron or diamond armour with enchantments such as thorns, fire protection and projectile protection. As most of you probably know, beds blow up in the nether, so don't take one unless you want to do some mining. As for food, take things that are stackable and provide a lot of hunger replenishment.
Step 2: Building Stuff
For your building materials you will need things like nether brick, brick, stone and glass. And obsidian, buttons, levers, sticky pistons, nether brick fence, glowstone, iron doors, redstone, repeaters, crafting tables, chests, furnaces and dispensers are necessary for this build.
Step 3: The Foundation
Find a large flat area and build a base at least 15 by 8 blocks wide using bricks and stone.
Step 4: Walls
Now place nether brick all around the foundation and one layer of glass on top of that.
Step 5: More Walls
Build a layer of stone on top of the glass, then break two blocks at the end of the structure for the door way. Place 12 nether brick to the sides of the door way as shown in pic 2.
Step 6: The Roof
Make the roof using nether brick and normal brick. Place an iron door on the outside of the door block and one nether brick in front of it as a door step. Place nether brick fence all around the the building, coming 2 blocks out in front of the door step.
Step 7: Defense Mechanism One
Enter the first door and place another door at the other end of the nether brick entrance with a button in front of it. Replace the two bricks at the side of the second door with dispensers. Place four of any block and two repeaters as shown in pic 3. Place down 4 redstone dust and a lever as shown in pic 4. The idea is that if pig-men are chasing you, you can go inside your base, and if they follow you through the first door you can load the dispensers with arrows and flick the lever a few times to kill any pig-men stuck between the doors.
Don't forget to add buttons on both sides of both doors.
Step 8: Base Defense Two
For the other line of defense, start by digging a two-block deep trench in front of your door, so that it fills in the gap in the fences. Place sticky pistons in the bottom of the trench and nether fence on top of it. Pic 4 is how it should now look. Dig a 2-by-2 block trench in front of the base and place down redstone and repeater in the way shown in pic 6.
Step 9: Base Defense Two Part Two.
Now dig some steps up from the trench into the the base and place redstone going up them as shown in pics 1, 2 and 3. Fill in the empty space above all the redstone and connect the redstone dust which leads up into the base to a lever. When you flick the lever, the pistons will push the fences up, forming a full perimeter around the base.
Step 10: Panic Room Part One
So the point of this is that if you are getting attacked by ghasts or suffering a pigman invasion, you can climb down to your obsidian-lined panic room where you have a chest, crafting table etc and wait till it is over. (Or just change to peacefull) So start by digging at least 4 blocks down at one end of your base, then widening out by a few blocks forward and to either side. Now replace all the surrounding blocks with obsidian, not forgetting the ceiling.
Step 11: Panic Room Part 2
Now place ladders up the wall to the surface, add glowstone or torches for light and a trapdoor at the top of the ladders for security. Put down your furnace, chest, crafting table etc (not a bed;) both in the panic room and in the main base. I would recommend placing glowstone both on top of the building so that pigmen don't spawn. Put down another fence in the same place as shown in pic 6.
I hope everyone has understood and liked this rather vague tutorial and if you have any questions, please leave a comment.