Marriage in Islam is Mithaq (Covenant) that has been divinely ordained as the following verses tell us.

'It is He Who has created man from water; then has He established relationships of lineage and marriage; for thy Lord has power (over all things)' -Q25V54

 

'..He created for you mates from among yourselves, that you may dwell in tranquility with them and He has put love and mercy between your hearts..' -Q30V21

The Prophet also said: '..you will see nothing conducive to love like marriage.' (Bukhari)

There are four necessary things to do to make a marriage valid in Islam. The steps are clear and anything done beyond theses four are extraneous and has no bearing on the ceremony itself.

1. Ijab Wal Qubul (Offer and Acceptance): In Islam, the man is required to make an offer of mariage to either the woman or her guardian who acts on her behalf. Regardless, the consent of the woman is also necessary. If the acceptance is accepted under duress at any point,m the marriage is not valid.

2. Mahr: A gift is given by the husband to the wife at the wedding. It can be anything so long it is mutually agreed by husband and wife. The Prophet (SAW) added: 'Marry, even with (a Mahr equal to) an iron ring.' - Bukhari 

'And give the women (on marriage) their Mahras a free gift.' -Q4V4

3. Waliyy: Guardians or parents can help negotiate the marriage contract on behalf of their wards. The consent of the wali of the woman is required. However if the objection to marriage lacks meit in Islam, the marriage can still be held as approved by the ummah.

4. Witness: Individuals with upright characters must be present to witness the exchange of the marital vows between the two parties.

After the aqdul Nikah, the bride is ushered to her husband's house in which the walima (feast) organized by him can start.. The walima must comes after all the marriage procedures have been completed. The simpler it is, the more the blessings of Allah on the couple.

The following are unislamic practices that over time have been introduced-

• Procreation before marriage
• Engagement ceremony
• Bachelors eve and Spinster's night
• Wedding dresses that contravenes Islamic modesty
• Inviting select people
• Extravagance and waste
• And Allah knows best. May Allah forgive me if I am wrong and guide us to the right path.  Ameen.

you can read Islamic Rites (Part 1) here