Step 1: Foundation

First of all, you need to find a fairly smooth area

Next, dig out a 7x7 hole in the ground

Fill the hole with cobblestone

Step 2: Walls

Surrounding the 7x7 patch of cobblestone build a 3 high wall of stone brick

Step 3: Wall Decoration

In a corner, place a cobblestone wall on the top and bottom. Then put a piece of red wool in the middle. Repeat for all 4 corners

On one wall, outside the stone brick, make this design (look at picture!)

Repeat for 2 other sides

On the final side make basically the same pattern but a little different for the door (again look at picture!)