This is how you sign Common in British Sign Language.

Description

To learn how to sign "Common" in British Sign Language (BSL) bring both hands together in a closed flat handshape both palms facing down, rotate them clockwise. Alternatively, your non dominant hand should be in an open flat handshape with palms facing upwards. Bring your dominant hand directly on top in a clenched fist with thumb extended and brush against it repeatedly with knuckles touching your palm