"A frog in his throat"--usually in reference to a person whose normal voice is altered, because of a cold, sore throat, laryngitis, or just not being fully awake in the morning, after a bad night.
"Put your foot down"--Stand firmly on what you have decided to do, or what you are requiring someone else to do. Often used by parents reigning in their child.
"Split our sides"--generally refers to laughing so hard, one's chest muscles want to tear.
"Laughing our heads off"--laughing so hard you feel your head will fall off.
"Pins and needles"--like sitting on pins and needles.