First of all, in order to understand the person, it must be good to know. Apart from superficial knowledge needed deeper to help you understand his point of view, thinking, desires and aspirations. It is equally important to have an idea of what is important, valuable and necessary. It is clear that you need a mutual desire to know each other. Given such moments in communication, you will be able to adjust and give in, and it is important in a relationship.
Another component in achieving understanding is the ability to respectfully communicate. Usually people behave more relaxed with those close to them, and sometimes because of that hurt each other. Therefore, it is important to remember that no matter how near and dear you are, respect should be in the first place. This means that you will tactfully speak, listen carefully to the person keeping him warm eye contact, take into account its internal state and interests, to show that mutual understanding between you is very important to you, and to pay reasonable attention to yourself and your needs in a conversation.
The habit of openly and honestly communicate, to express their concerns and feelings will help to see what gaps there are in your relationship and fill them. It is a hard and painstaking work, the result of which will be apparent only after a time, but it will exceed all your expectations. Therefore, for the sake of understanding should try.
However, if only one person is trying, it is inefficient, although it is likely that the second eventually relent and notice your diligent efforts, and will be ready to respond in kind. But we should not lose sight of the fact that the efforts of one can not be in vain. So make sure that you both want to understand and are willing to make efforts towards achieving it.