As with most home improvement projects, it's best not to just jump right into the fire. Before you begin building a fire pit, you'll need to do some prep work first. Be sure to check with your local municipal authorities to make sure it is legal to light an open fire in your neighborhood.
Now you'll need to plan the right spot for your pit. Keep in mind how the wind will blow the smoke around, so don't put it too close to open doors or windows. Leave room to walk around the pit and be sure that it's not near any plants, fences, buildings or structures that could be potential fire hazards.
Use cement blocks or bricks to build the walls of your fire pit. See how your cement blocks or bricks will lie by putting down a "test" ring of them. This will give you an idea of the size and shape of the pit so you can dig accordingly. The ideal size for a fire pit is about 4' in diameter. You may have to cut a block or two to fit into the ring. Use a chisel and brick hammer to mark a line around the entire block to suit the size you will need to fit the brick into your layout, and then split the block along the line. Smooth out any jagged edges with the brick hammer. Make sure the chiseled rock fits snugly with the blocks adjacent to it.