Push a safety pin through the ribbon and through a piece of clothing to attach the ribbon to a person's clothing. Close the pin once the ribbon is connected.
Staple the ribbon to the paper if the ribbon is being presented with a certificate as part of an award. Ribbon is a very light material and a stapler should punch right through it.
Tie the ribbon in a traditional knot around any other object you are attaching the ribbon to. This is effective for gifts after they have already been wrapped.
Use hot glue to stick a ribbon to something you don't want to use a pin or a stapler on if tying is not an option.