Instructions
Craft any kind of pickaxe. This requires wood and another material of your choice, such as more wood, cobblestone or iron ingots. The material of the pickaxe is not important for crafting a stone sofa.
Locate stone blocks, found abundantly in caves and underground. Stone blocks are primarily light gray with few flecks of dark gray scattered on the surface. Hold down the left mouse button while holding your pickaxe to harvest cobblestone from the stone.
Right-click on any furnace to bring up a dialog box with three squares. Two squares are on the left side while one square is on the right side and a clear arrow separates the two columns. Place a source of fuel, such as coal or wood, into the bottom left square and place a stack of cobblestone in the top square. The arrow will begin to slowly fill with white, indicating you are smelting the stone. Cobblestone smelts back into regular stone.
Right-click any crafting table to bring up a 3-by-3 grid. Fill the bottom row with pieces of stone to create stone slabs. The slabs will serve as the cushions of your sofa.
Prepare a 2-by-4 area of space, which will serve as the ground where you will place the sofa. Hold the whole stone blocks in your hand and right-click where you want to place them. For a basic sofa, place four blocks of whole stone next to each other horizontally, which will be your sofa's back support. Place another block of stone in front of the first and fourth block in the line, which will be the sofa's armrests.
Hold the stone slabs in your hand and right-click them to place them. Place two slabs in between the two armrests, serving as the cushions and completing your sofa.
Walk onto the cushions and face away from the back support. Press "Ctrl" to crouch and mimic the sitting position.