How to make a Nether Portal and an End Portal

To make a Nether Portal, you first need to gather at least 10 blocks of obsidian. Obsidian is created when you pour water over a pool of lava, and the most efficient way to harvest it is using a diamond pickaxe. Then you need to make a rectangle. Nether Portals are always 4x5 at the minimum, but can be 23x23 at the maximum. A good way to save time and resources, as well as durability on your pickaxe, is not using the corners. A Nether Portal will work without the corner blocks. Finally, to light your Nether Portal, use a source of fire such as a fire charge or a flint and steel to light your portal. If you have built it correctly, swirling purple portal blocks will appear inside the frame, as well as purple particles being drawn into those portal blocks. A partner Nether Portal will generate in the Nether when you build a Nether Portal in the Overworld, and a partner Nether Portal will generate in the Overworld if you do the reverse.
 In Pocket Edition, there is no Nether before Update 0.12.1, in which the Nether Reactor was removed and regular Nether Portals were added. Now I will show you how to create a Nether Reactor.
 First, you will need a Nether Reactor Core. You can create one by placing 3 diamonds and 6 iron ingots into the crafting interface, in the pattern shown in the picture to the right. That will give you 1 Nether Reactor Core.
 You will also need 4 gold blocks and 14 cobblestone.
 The first step is to place five cobblestone on the ground in a plus shape. Then place the gold blocks, one in each corner.
 The second step is to make an X using 4 cobblestone and your Nether Reactor Core. You first need to place one cobblestone block on each gold block, and then the Nether Reactor Core in the center.
 The third step is the top layer. Repeat the first step, but without the gold blocks in the corners.
 The fourth step is to activate your Nether Reactor. For this step, you will need to be in Survival Mode. Once in Survival Mode, tap the Nether Reactor Core in the center.
 If you have built your Nether Reactor correctly, you will be surrounded in a Nether-like world around you, with the word Active! in the right upper-hand corner. If you want to keep your gold blocks to make a new Nether Reactor or for a different purpose, mine them quickly before they disappear. After that time, you will need to run around and collect all of the items from the Nether before you are left with a large Netherrack structure with holes in the walls that appears when your time is up.

End Portals are a little harder to make. You will need 12 End portal blocks, and the only methods of getting an End Portal block is by a) being in creative mode or b) using commands. First, place three End portal blocks down in front of you. Then, place more End Portal blocks down in a square around you, but without corners. IMPORTANT: MAKE SURE THE GREEN TABS ARE FACING INWARDS.

 Now your End Portal should look like this. When you have finished the frame of your End Portal, start placing the Eyes of Ender. You will need 12 of them. You can procure 1 Eye of Ender by placing blaze powder and an Ender Pearl next to each other in a crafting table. Make sure the dark teal outside of the black center on each Eye of Ender is pointing towards both the inside and the outside of the frame, instead of to both sides of the portal.

Your End Portal should look like this. If it does, then congratulations! You have built your very own End Portal.