Some relevant points to be noted are:
Engagement
or Mangni does not qualify the future spouses to go out together, even if the parents consent. Man and woman become permissible for each other only after the performance of Nikah.
Dowry
The unislamic system of demanding and accepting dowry must be avoided at all costs. Shariah does not make any expense incumbent on the bride/bride’s parents. Even the marriage expenses, it is recommended are to be borne by the bridegroom.
However, the bride can bring whatever she wants of her free will, and it will always belong to her.
Other Unislamic Customs
Many other unislamic customs have crept into the marriage ceremony of some Muslims. These customs are either borrowed from non-Muslim cultures or continue because they are established in past generations. One must avoid them if they are against the Shariah, even if some people are displeased. Other customs like the breaking of coconut etc. also do not feature among the Islamic rituals. All actions, customs etc. which show disrespect to Islam or weaken the importance of Islam have to be avoided.
Haraam Acts
Some of the rituals in marriage ceremonies are absolutely haraam like the playing of music. It is also haraam for ladies to go for mixed gatherings without proper hijab. Such things invite divine wrath and take away the blessings of this auspicious occasion.