Engagement  in Islam
Question

What is the concept of engagement in Islam? Usually an engagement party is one in which the fiance/fiancee exchange rings. Is this the prescribed method in the shariah?
Praise be to Allah.What is engagement in Islam?
Engagement in Islam means that a man asks to marry a woman and is accepted. The view of the scholars is that engagement is prescribed for one who wants to get married. Allah says (interpretation of the meaning): {And there is no sin on you if you make a hint of betrothal…} [Al-Baqarah 2:235]
It was narrated that the Prophet (peace and blessings of Allah be upon him) got engaged to `Aishah. (Al-Bukhari, An-Nikah, 4793) It is also stated in Al-Bukhari and Muslim  that the Messenger (peace and blessings of Allah be upon him) got engaged to Hafsah. (Al-Bukhari, An-Nikah, 4830) 
Looking at prospective wife I Islam
The Messenger of Allah (peace and blessings of Allah be upon him) encouraged the one who wants to get engaged to look at the woman to whom he wishes to propose . According to the Hadith, “When any one of you proposes marriage to a woman, if he can look at that which will encourage him to go ahead and marry her, then let him do so.” (Abu Dawud, An-Nikah, 2082; classed as sound by Al-Albani in Sahih Abu Dawud, 1832) 
Prohibited Practices in Engagement in Islam
But in Islamic Shari`ah there are no specific practices that must be followed with regard to engagement. What some Muslims do, announcing the engagement, having a party to celebrate and exchanging gifts, all comes under the heading of customs which are permissible in principle, and none of them are prohibited except those which Shari`ah indicates are prohibited – which includes the exchange of rings between the engaged couple , a custom which is known in Arabic as “Diblah.” This custom goes against Shari`ah for the following reasons: 

Some people think that these rings increase the love between the spouses and have an effect on their relationship. This is an ignorant (Jahili) belief and is an attachment to something for which there is no basis in Shari`ah and which does not make sense.  
This custom involves imitating the non-Muslims such as Christians and others. It is not a Muslim custom at all. The Messenger (peace and blessings of Allah be upon him) warned us against that when he said, “You will inevitably follow the paths of those who came before you, handspan by handspan, cubit by cubit, until even if they entered the hole of a lizard, you will follow them.” We said, “O Messenger of Allah,  (do you mean) the Jews and Christians?” He said, “Who else?” (Narrated by Al-Bukhari, Al-I`tisam bil Kitab was-Sunnah, 6889 and Muslim, Al-`Ilm, 6723) 

And the Prophet (peace and blessings of Allah be upon him) said: “Whoever imitates a people is one of them.” (Narrated by Abu Dawud, Al-Libas, 4031; classed as authentic by Al-Albani in Sahih Abu Dawud, 3401)

This engagement usually takes place before the marriage contract , in which case it is not permissible for the man to put the ring on his fiancée’s hand himself, because she is still a stranger (non-Mahram) to him, and has not yet become his wife. 

Finally, we will quote the words of Shaykh Ibn `Uthaymin (may Allah have mercy on him) on this matter: 
“‘Diblah’ is a word that refers to the engagement ring. In principle there is nothing wrong with rings (i.e., they are permissible), unless they are accompanied by certain beliefs, as some people do when the man writes his name on the ring that he gives to his fiancée, and the woman writes her name on the ring that she gives to her fiancé, believing that this will guarantee the bonds between the spouses. In this case this ‘Diblah’ or engagement ring is haram, because it represents an attachment to something for which there is no basis in Shari`ah and which does not make sense. Similarly it is not permissible for the man to put the ring on the woman’s hand himself, because she is not yet his wife, so she is still a stranger (i.e., non-mahram) to him; she is not his wife until after the marriage contract is done.” (Al-Fatawa Al-Jami`ah lil Mar’ah Al-Muslimah, 3/914).
And Allah knows best.