The lava mold technique was shown on a previous achievment hunters, which is how I craft mine... Fun fact, you don't need the corners, as long as the 3x2 space has obsidian surrounding it, the portal will pop, saves you 4 blocks
I'm sorry, but that's a lame tutorial for Nether portals. All you need are some buckets for lava and to make a mold for the blocks of obsidian. You can make the molds into the shape of the portal.
Once you're inside the nether, you need to make another one inside to portal to another place in your world.
"If you create a portal in the Nether and re-enter the normal world, any distance covered in The Nether is multiplied by 8, effectively making The Nether a fast travel zone that allows for greater distances to be covered in a short amount of time in the normal world."
