Cover the entire floor with a large area rug or carpeting. This will prevent sound from traveling through the floorboards.
Secure cotton fabric to the ceiling with tacks or staples.
Place fabric over the tops of all hard surfaces, such as tables and chairs.
Put up thick curtains in front of any windows, and close them while you are playing the drums.
Furnish the room with soft furniture and accessories, like pillows. Place them all around the room to absorb the sound.
Cover the walls or specialty soundproofing foam, which you can purchase at large department stores and home décor stores. You can simply lean the foam up against the walls or attach it with durable tape.