He wants to see the Prophet (peace and blessings of Allaah be upon him) in a dream
Question

What is the best way to see Prophet Muhammad in a dream??.
Praise be to Allah.There is no way prescribed in sharee’ah for the one who wants to see the Prophet (peace and blessings of Allaah be upon him) in a dream. It is appropriate here to comment on a number of matters that have to do with this question: 
1 – The one who sees the Prophet (peace and blessings of Allaah be upon him) in a dream has to see him in his true form, at any stage of his life. So if a person claims to have seen light or a man with a completely white beard or a man wearing pants for example, these are not attributes of the Prophet (peace and blessings of Allaah be upon him), so this is not the Prophet (peace and blessings of Allaah be upon him). The Shaytaan cannot appear in the true image of the Prophet (peace and blessings of Allaah be upon him), but he can appear in other forms. 
It was narrated that Abu Hurayrah said: I heard the Prophet (peace and blessings of Allaah be upon him) say, “Whoever sees me in a dream will see me when he is awake, and the Shaytaan cannot take my shape.” Al-Bukhaari said: Ibn Sireen said: If he sees him in his true image. 
Narrated by al-Bukhaari, 6592; Muslim, 2266 
If a man told Ibn Sireen that he had seen the Prophet (peace and blessings of Allaah be upon him) [in a dream], he would say, “Describe to me the one whom you saw.” If he gave a description that he did not recognize, he would say, “You did not see him.” Its isnaad is saheeh. 
Al-Haakim narrated via ‘Aasim ibn Kulayb (who said), my father told me: I said to Ibn ‘Abbaas, “I saw the Prophet (peace and blessings of Allaah be upon him) in a dream.” He said, “Describe him to me.” He said, “I mentioned al-Hasan ibn ‘Ali and said that he looked like him.” He said, “You did indeed see him.” Its isnaad is jayyid. 
See Fath al-Baari, 12/383, 384. 
2 – The Muslim should not concern himself with dreams and visions, basing his affairs on them and forgetting about the state of wakefulness in which Allaah has enjoined rulings and acts of worship on him. 
3 – The Muslim who is following the Sunnah sees the Prophet (peace and blessings of Allaah be upon him) in his heart; the more he follows him the more he will see him. So when he goes out of his house or goes to the mosque or does wudoo’, he remembers what the Prophet (peace and blessings of Allaah be upon him) used to do. When he prays or performs Hajj he follows his Sunnah. When he buys and sells or interacts with people, he acts according to the teachings of his Prophet (peace and blessings of Allaah be upon him). When he is at home with his family and children he follows the teachings of his Prophet (peace and blessings of Allaah be upon him). 
This is what the Muslim should seek and strive to achieve. 
And Allaah is the Source of strength.