Short answer
Families should avoid extravagance, harmful customs, financial coercion, dowry demands and practices that contradict Islamic principles.
Islamic Guidance
What Islam teaches
Islam prohibits waste, injustice and consuming wealth wrongfully, while encouraging kindness and moderation.
Practical Guidance
What you can consider
Keep religious requirements clear, eliminate unnecessary competition and ensure that neither family is financially coerced.
Sources
Qur'an 7:31; Qur'an 2:188; Qur'an 5:2.