You can improve your chances of getting what you want if you prepare for the negotiation process. When approaching negotiations with a seller, think about what you want out of the deal. Try to send in your agent for the crucial conversations, if possible.
If you do have to participate in a conversation with the seller and/or their representatives that absolutely cannot be left to your agent, then take some time to practice your communication skills. You want to be able to communicate your point and get the information you want without giving too much information away. Take time to practice your facial expression and voice control. This may sound silly – and it may feel silly to do, at least at first – but practicing an inscrutable facial expression and an even tone of voice could help you avoid problems in your transaction.