Step 1: Creating
In order to find Herobrine the world generator seed must be "Need Water" with capitals and spaces. Name your world whatever you want; it doesn't matter.
Step 2: Spawn Point
Here is your spawn point. Get the sugar canes to make paper, books, bookshelves for decoration.
Step 3: Material
You will need a bunch of wooden planks. Note that Herobrine can open doors and climb ladders but he cannot open trapdoors. He can also teleport...
Step 4: House
I suggest making a sand house to not waste wooden planks. Make a crafting table and with it's help make a wooden door. Do not go deep mining yet before having a bed and at least ten torches.
Step 5: Shallow Mining
Now that you've made a pick axe and have ten torches dig down around fifteen blocks. You will find cobblestone. Make a stone pick axe in case you find iron. I also recommend a stone sword.
Step 6: Later...
I have been playing for around 18 Minecraft days, I've dug up my old house and made glass out of it. My new house is huge...
Step 7: My New House
Here is my new castle/fortress/mansion that has seven floors and six beds. I used my old house to make the glass on the first floor. It took me 25 Minecraft days to finish. Can you beat me? Leave your answer in the comments. I hope you enjoyed my instructable and I wish you luck on your manhunt for HEROBRINE!