Lay a soundproofing material, like cork underlayment or acoustic flooring underlayment, prior to installing the flooring in second-floor rooms if the main flooring hasn't been installed yet. Cork underlayment and acoustic underlayment each create a noise barrier between floors and can be laid under many types of flooring, including hardwood and carpet. Both types of underlayment install directly to a subfloor with adhesive.
Carpet the floor to create a soft base that absorbs footsteps and sounds. For increased noise reduction, line the floor beneath the carpet with a cork or foam underlayment.
Add rugs to hard flooring surfaces. As with carpets, line the floors beneath rugs with a sound-absorbing underlay, such as cork or foam, or with a carpet pad cut down to the size of the rug. Space rugs where you can walk across the room without having to step on the hard floor surface to quiet footfalls.
Cover the floor with rubber floor tiles if the room's main flooring has already been installed and you don't want to pull up the flooring to install a soundproofing underlayment. Lock the rubber floor tiles together on their edges to line the entire floor. Rubber floor tiles may be installed over any type of flooring, but stay together most effectively, and provide the most sound reduction, on hard floors.
Line the walls of second-floor rooms with curtains or acoustic panels if you want to soundproof the entire room. Hang curtains with standard curtain rods or by pinning the curtains directly to the walls. Acoustic panels generally come with their own installation hardware, which consists of a hanger and screws, much like the hardware that comes with a picture frame.