--A deliberately raised eyebrow
--A tilt of the head
--Stiffening posture
--A bemused smile
--Asking questions that imply you already know the answer or asking loaded questions
--A too-sweet tone
--Choosing words that cut/degrade/diminish
--A roll of the eyes
--Raising the chin so to create the idea you're looking down at someone
--Sharing an unkind look with others, drawing attention to the object of sarcasm
--Arms crossing the chest
--A stance that conveys haughtiness/power
--Making little or no attempt to hide disrespectful amusement
--A smirk or sneer
--A hand wave that dismisses someone as unimportant
--Raising the voice to draw attention to one's words
--Tossing out a rapid, snappy response
--A languid hand gesture that suggests you want the other person to speak or take the floor when it's clear you think they'll only prove their idiocy
--Encouraging someone to please add their thoughts in a tone that suggests they have nothing worthy to add
--Adding a low blow or derogatory comment to 'slam dunk the moment'
--Muttering or belittling under the breath, just enough to be heard
--Narrowed eyes, eyes glittering with a hard or unkind amusement
--Raising hands in the 'I give up gesture' and backing away, but with a smile that suggests you still feel they are in the wrong but it isn't worth the battle
--Shaking the head while another is speaking
--Comparing the situation with another time where the person made a costly mistake "Oh, just like you did before, huh?"
--A loud smacking of the lips or tsk-ing in a condescending manner
--Verbally agreement infused with impatience or rudeness "Okay, sure. Whatever you say."
--Parroting someone else's words, but in such a way to make them sound ridiculous (and therefore the idea behind them ridiculous)
--Making someone the center of attention in a negative way
--Belittling one's ideas, words or viewpoint
--Pursing lips
--Asking questions geared to discomfort the other person
--A toss of the head
--Using one's stance/ideas as a platform to jump to conclusions: "You say Jill should decide if she wants to watch the horror movie. Should we let her rent porn or whatever else too?"