If you want to make the other person feel uneasy during the exchange,then look at their hairlin.
If you're faced with a gushing conversation people who don't give you room to talk at all,just pretend to be in front of him slip something down,maybe it's your pen,it could be a notebook in your hand ,then squat down and pick it up,now it's your turn to speak .
If you ask the other person a question ,the other party only answered part of the answer,then you can choose to be silent ,and keep eye contact,the other person usually continues to answer .